KR20170044523A - Microorganism producing L-threonine and process for producing L-threonine using the same - Google Patents

Abstract

The present invention relates to a microorganism producing L-threonine, and a method for producing L-threonine using the same. When using the microorganism producing L-threonine in which activity of CobB protein is inactivated compared to immanent activity, an NAD(H) level in cells is increased so L-threonine can be produced with high efficiency and high yield.

Description

The present invention relates to a microorganism having L-threonine producing ability and a method for producing L-threonine using the L-threonine producing process.

The present invention relates to a microorganism having L-threonine producing ability and a method for producing L-threonine using the same.

L-threonine is an amino acid widely used as a feed additive, a pharmaceutical raw material or a food raw material, and is mass-produced by a fermentation method using microorganisms.

The method of producing a target substance using microorganisms mainly uses a target substance-specific approach such as increasing the expression of a gene encoding an enzyme involved in the production of a target substance, or removing a gene that does not require expression. On the other hand, since the production and maintenance of sufficient energy is required for high-yield production of the target substance, energy in the form of NADH, NADPH and adenosine-5'-triphosphate (ATP) Is also used.

Methods for increasing the level of NAD (H) in microorganisms include increasing the synthesis of genes involved in de novo biosynthesis or salvage processes and decreasing the degradation pathway of NAD (H) (Metabolic Engineering, 2002, 4, 238-247) is known as a method of strengthening by attenuation or deletion. On the other hand, CobB is known to be complexed with superoxide lysine of histone H4 protein as a denitration oxidase or a dormant mycotic enzyme, and Zn ²⁺ binding site is known to exist (J Mol Biol, 2004, 337 (3) ; 731-41).

Under these circumstances, the present inventors have made efforts to increase the NAD (H) required for biosynthesis of a useful target substance such as L-amino acid. As a result, the inventors discovered the cobB gene and manipulated the gene to yield L- The present invention has been completed.

It is an object of the present invention to provide a microorganism having L-threonine producing ability.

Another object of the present invention is to provide a method for producing L-threonine using microorganisms having L-threonine producing ability.

In order to achieve the above object, the present invention provides, in one embodiment, a microorganism wherein the activity of the CobB protein has an inactivated L-threonine producing ability relative to the intrinsic activity.

In the present invention, the term "CobB protein" may refer to a protein lysine deacetylase and / or a protein lysine desuccinylase. NAD (H) Lt; RTI ID = 0.0 > III < / RTI > sirtuin protein using as a cofactor. The CobB may contain an enzyme having an activity similar to that of the enzyme even if the enzyme has a different name, for example, it may be an enzyme derived from Escherichia sp. Specifically, the CobB protein may include the amino acid sequence of SEQ ID NO: 1. In addition, the CobB protein may be a protein having 70% or more, 80% or more, 90% or more, or 95% or more of sequence homology with the amino acid sequence of SEQ ID NO: 1. The CobB protein is a sequence having such homology, and includes, without limitation, substantially the same or a function corresponding to each of the above proteins. If the amino acid sequence has such homology, it is understood that the CobB protein also includes amino acid sequences in which some amino acid sequences are deleted, modified, substituted or added as compared to the wild-type CobB protein.

In addition, the gene encoding the CobB protein of the present invention may encode an amino acid sequence having the sequence homology of 70% or more, 80% or more, 90% or more, or 95% or more with the amino acid sequence of SEQ ID NO: 1 . As a specific example, the cobB gene may have 70% or more, 80% or more, 90% or more, or 95% or more of sequence homology with the nucleotide sequence of SEQ ID NO: 2. The cobB gene may include, without limitation, as long as it encodes a protein having the same or equivalent function as the CobB protein. Also, it is understood that a gene having such homology includes a gene in which some nucleotide sequences are deleted, modified, substituted or added compared to the wild-type cobB gene.

The term "homology" in the present invention means a nucleotide sequence or a similar degree of amino acid sequence of a gene encoding a protein. That is, the percentage of identity between two polynucleotides or polypeptide mimetics. The homology between sequences from one moiety to another can be determined by techniques known in the art. For example, homology can be determined by aligning the sequence information and directly aligning the sequence information between two polynucleotide molecules or two polypeptide molecules using a computer program that is readily available. The computer program may be BLAST (NCBI), CLC Main Workbench (CLC bio), MegAlign ^TM (DNASTAR Inc), and the like. In addition, homology between polynucleotides can be determined by hybridizing the polynucleotide under conditions that form a stable double strand between homologous regions and then resolving the single-strand-specific nucleases to determine the size of the resolved fragment.

As used herein, the term "intrinsic activity" refers to the level of activity of a protein that originally has microorganisms in their pre-modification or natural state.

In the present invention, the term "the activity of a protein inactivated relative to an intrinsic activity" means that the protein mentioned in the microorganism is not expressed at all, or that the protein is not active at all or that the activity of the protein is weakened or eliminated . As used herein, the term "attenuating" or "ablating" protein activity means that the expression of the gene encoding the protein is reduced or not present at any level.

Examples of a method of inactivating the activity of the protein include a method of replacing the gene encoding the protein on the chromosome with a gene mutated so that the activity of the protein is reduced or absent; A method of introducing a mutation into an expression control sequence of a gene on a chromosome encoding the protein; A method of replacing the expression control sequence of the gene encoding the protein with a sequence having weak or no activity; Deletion of all or part of the gene on the chromosome encoding the protein; A method of introducing an antisense oligonucleotide (for example, antisense RNA) that binds complementarily to a transcript of a gene on the chromosome and inhibits translation of the mRNA to a protein; A method of artificially adding a sequence complementary to the SD sequence to the SD (Shine-Dalgarno) sequence of the gene encoding the protein to form a secondary structure to make it impossible to attach the ribosome, ), And the reverse transcription engineering (RTE) method in which a promoter is added so as to be reverse-transcribed to the 3 'end of the gene.

Specifically, a method of deleting a part or all of a gene encoding a protein includes a step of inserting a polynucleotide encoding an intrinsic target protein in a chromosome through a vector for insertion of an intrabacterial chromosome into a polynucleotide or marker in which part or all of the nucleotide sequence has been deleted Gene. ≪ / RTI > As an example of a method of deleting a part or all of these genes, a method of deleting genes by homologous recombination can be used. The "part" may be, for example, 1 to 700 nucleotides, 1 to 500 nucleotides, 1 to 300 nucleotides, 1 to 100 nucleotides, or 1 to 50 nucleotides, depending on the type of the polynucleotide. The term " homologous recombination "as used herein refers to genetic recombination occurring through ligation at the locus of a gene chain having homology with each other. In a specific embodiment of the present invention, the protein was inactivated by homologous recombination.

Also, a method of modifying an expression control sequence may be performed by inducing a mutation in the expression control sequence by deletion, insertion, non-conservative or conservative substitution or a combination thereof in the nucleotide sequence of the expression control sequence, or by replacing with a weaker promoter And the like. The expression control sequence may include a promoter, an operator sequence, a sequence encoding a ribosome binding site, and a sequence regulating termination of transcription and translation.

In addition, a method of modifying a gene sequence on a chromosome may be performed by inducing a mutation in a sequence to delete the gene sequence, deletion, insertion, non-conservative or conservative substitution or a combination thereof so that the activity of the protein is further reduced, Or by replacing the gene sequence with an improved gene sequence or an improved gene sequence so that there is no activity.

The term "microorganism producing L-threonine" or "microorganism having L-threonine producing ability" in the present invention means a microorganism having naturally occurring L-threonine production ability or a microorganism having L- Means a microorganism to which the production ability of threonine is imparted to a naturally occurring strain without production capacity.

In the present invention, the microorganism having L-threonine producing ability may include all microorganisms that produce L-threonine capable of inactivating the activity of the CobB protein of the present invention. Examples include Escherichia (Escherichia), An air Winiah (Erwinia) genus, Serratia marcescens (Serratia) genus, Providencia (Providencia) genus Corynebacterium (Corynebacterium) in and Brevibacterium genus Solarium (Brevibacterium) But are not limited to, microorganisms. Specifically, the microorganism having L-threonine producing ability of the present invention may be Escherichia genus, more specifically, E. coli .

In another aspect, the present invention provides a method for producing L-threonine, comprising culturing an Escherichia genus microorganism having L-threonine producing ability inactivated of CobB protein in a medium; And obtaining L-threonine from the microorganism or culture medium.

The microorganism having L-threonine producing ability or the Escherichia genus having L-threonine producing ability is as described above.

The cultivation may be carried out in accordance with a culture medium and an appropriate medium known in the art. In addition, a person skilled in the art can easily use the culture medium and culture conditions. Specifically, the culturing can be carried out continuously in a batch process, an injection batch, or a fed batch or repeated fed batch process, but is not limited thereto.

The medium must meet the requirements of a particular strain in a suitable manner and may be suitably modified by a person skilled in the art. Sugars which may be used include sugars and carbohydrates such as glucose, sucrose, lactose, fructose, maltose, starch and cellulose, oils and fats such as soybean oil, sunflower oil, castor oil, coconut oil, palmitic acid, But are not limited to, fatty acids such as linoleic acid, alcohols such as glycerol, ethanol, and organic acids such as gluconic acid, acetic acid, and pyruvic acid. These materials may be used individually or as a mixture. Examples of nitrogen sources that may be used include peptone, yeast extract, gravy, malt extract, corn steep liquor, soybean meal and urea or inorganic compounds such as ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium carbonate and ammonium nitrate, But is not limited thereto. The nitrogen source may also be used individually or as a mixture. The number of people that can be used includes, but is not limited to, potassium dihydrogenphosphate or dipotassium hydrogenphosphate or the corresponding sodium-containing salts. In addition, the culture medium may contain a metal salt such as magnesium sulfate or iron sulfate necessary for growth. In addition to these materials, essential growth materials such as amino acids and vitamins may be used. In addition, suitable precursors for the culture medium may be used, but are not limited thereto. The above-mentioned raw materials can be added to the culture medium in a batch manner or in a continuous manner by an appropriate method.

Basic compounds such as sodium hydroxide, potassium hydroxide, ammonia, or acid compounds such as phosphoric acid or sulfuric acid can be used in a suitable manner to adjust the pH of the culture. In addition, bubble formation can be suppressed by using a defoaming agent such as a fatty acid polyglycol ester. Oxygen or oxygen-containing gas (e.g., air) may be injected into the culture medium to maintain aerobic conditions. The temperature of the culture medium may be usually 20 ° C to 45 ° C, for example, 25 ° C to 40 ° C, or 30 ° C to 40 ° C. The incubation period can be continued until the desired amount of L-threonine is produced, for example 10 to 160 hours, or 10 to 72 hours. L-threonine may be released into the culture medium or contained in the cells.

The step of obtaining L-threonine of the present invention includes a step of isolating L-threonine from a microorganism or a medium, specifically, a culture medium or a culture medium from which cultured microorganism cells or microbial cells have been removed . The method for isolating and obtaining L-threonine from the culture medium or the culture medium from which the microorganism or microbial cells have been removed can be obtained by using a suitable method known in the art according to the culture method. For example, it is possible to carry out a treatment with a protein precipitant (for example, salting-out), centrifugation, extraction, ultrasonic disruption, ultrafiltration, dialysis, chromatography including gel filtration, adsorption chromatography, ion exchange chromatography, affinity chromatography And the like, and combinations thereof. However, the present invention is not limited thereto.

The separating step may include a purification step.

When the microorganism having an inactivated L-threonine producing ability as compared with the intrinsic activity of the CobB protein in the present invention is used, the level of NAD (H) in the cell is increased and L-threonine Can be produced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing intracellular NAD (H) levels of a strain having L-threonine producing ability according to an embodiment.
FIG. 2 is a diagram showing intracellular NAD (H) levels of a strain having L-threonine producing ability according to an embodiment.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are intended to illustrate the present invention, and the scope of the present invention is not limited by these examples.

Example 1. cobB Of Escherichia coli strain

1. In E. coli wild type strain cobB Of strain deficient

In this embodiment, by deletion, by the cobB gene from the E. coli W3110 (ATCC 39936) wild-type E. coli strain homologous recombination was produced in a strain with a cobB gene deletion. In E. coli, the cobB gene is known to encode a protein lysine deacetylase activity and / or CobB protein having protein lysine desuccinylase activity. The cobB gene to be deleted has the nucleotide sequence of SEQ ID NO: 2.

The specific procedure for deletion of the cobB gene by homologous recombination in E. coli W3110 is as follows. For the deletion of the gene cobB , a one step inactivation method using lambda Red recombinase developed by Datsenko KA et al. (Proc Natl Acad Sci USA, (2000) 97 : 6640-6645).

First, the chloramphenicol gene of pUCprmfmloxP, which is a marker for confirming insertion into the gene, was prepared as follows. (gDNA) of Escherichia coli W3110 was extracted using a Genomic-tip system (Qiagen, Germany) to obtain 0.3 kb of a DNA fragment containing the promoter of rmf gene. Using the gDNA as a template, Polymerase chain reaction (PCR) was performed using the polynucleotide of SEQ ID NO: 4 as a primer. The PCR for amplifying the above PCR was performed 30 cycles of denaturation at 94 DEG C for 30 seconds, annealing at 55 DEG C for 30 seconds, and elongation at 72 DEG C for 2 minutes and 30 seconds. The obtained PCR product was digested with KpnI and EcoRV, and electrophoresed on 0.8% agarose gel, followed by elution to obtain a 0.3-kb Prmf fragment. Subsequently, the obtained Prmf fragment and pUC19 (New England Biolabs, USA) (Accession Number L09137) were digested with restriction enzymes KpnI and SmaI, respectively, and ligation was performed to prepare a pUC-Prmf plasmid. Next, a pUCYC184 plasmid (Accession Number X06403) (Accession Number X06403) was used as a template and a plasmid pUCYC184 (SEQ ID NOs: 5 and 6) was used as a template to construct a vector pUCprmfmloxP having a mutant loxP-CmR- loxP cassette and an rmf gene promoter simultaneously Using a polynucleotide as a primer, a PCR consisting of 30 cycles of denaturation at 94 DEG C for 30 seconds, annealing at 55 DEG C for 30 seconds, and extension at 72 DEG C for 1 minute was repeated 30 times to obtain a 1.1 kb PCR product. The 1.1 kb DNA obtained by the PCR using the pUC-Prmf vector and pACYA184 as templates was digested with restriction enzymes NdeI / KpnI, followed by ligation reaction, and the resulting ligation product was transformed into E. coli. From the transformed Escherichia coli, cell lines having DNA correctly lyped by a conventional method were selected and the plasmid pUCprmfmloxP was isolated and purified from the culture.

Thereafter, pUCprmfmloxP was used as a template using a primer combination of SEQ ID NOS: 7 and 8 having a nucleotide sequence of a portion of the cobB gene and a nucleotide sequence of a chloramphenicol resistance gene of pUCprmfmloxP, followed by denaturation at 94 DEG C for 30 seconds, annealing at 55 DEG C for 30 seconds, And extension at 72 ° C for 1 minute. The PCR product of about 1.3 kb was obtained by a first round of PCR. The obtained PCR product was electrophoresed on 0.8% agarose gel and eluted, and used as a template for the second PCR. The secondary PCR was performed using the eluted primary PCR product as a template, using the primer combinations of SEQ ID NOs: 9 and 10, including the 20 bp base sequence of the 5 'and 3' regions of the PCR product obtained in the first PCR , Followed by denaturation at 94 DEG C for 30 seconds, annealing at 55 DEG C for 30 seconds, and extension at 72 DEG C for 1 minute, and a secondary PCR product of about 1.3 kb was obtained by a second PCR . The obtained secondary PCR product was electrophoresed on 0.8% agarose gel, eluted and used for recombination.

Thereafter, Escherichia coli W3110 (hereinafter referred to as " pKD46-introduced Escherichia coli W3110 ") transformed with the pKD46 vector (Accession Number AY048746) according to the one-step inactivating method developed by Datsenko KA, ), The secondary PCR product was introduced into pKD46- introduced E. coli W3110 through electroporation. Next, the second PCR product and pKD46-introduced E. coli W3110 were cultured in LB medium containing chloramphenicol to select a primary recombinant strain having chloramphenicol resistance. Next, in order to remove the chloramphenicol marker gene from the recombinant strain, the pKD64 vector was firstly removed from the recombinant strain. Then, the pJW168 vector (Gene, (2000) 247, 255-264) having the Cre-recombinant enzyme gene was introduced into the recombinant strain from which the pKD64 vector had been removed, and the pJW168 vector was added to express the Cre- recombinase from the introduced pJW168 vector The introduced recombinant strains were cultured in LB medium containing ampicillin at 30 ° C. Then, isopropyl-beta-D-1-thiogalactopyranoside (IPTG) was plated on the medium to select strains. The selected strains were genetically recombined at the mutant loxP site by the Cre-recombinant enzyme and the chloramphenicol marker gene was removed. Then, the strain in which the chloramphenicol marker gene was removed was cultured at 42 ° C. to remove the pJW168 vector. Finally, the obtained strain was named W3110_ΔcobB . Then, about 0.5 kb PCR products obtained by PCR using the primers of SEQ ID NOS: 11 and 12 were used to amplify cobB It was confirmed that the gene was deleted.

The CobB named the W3110_ △ cobB the activity of the protein is inactivated by CA03-8300 and, under the Budapest Treaty on December 05 2014 date to deposit the Korea Culture Center microorganisms (KCCM) were given an accession number KCCM11630P.

2. Threonine  In strains with enhanced metabolic pathways cobB  Production of defective strains

In this embodiment, to enhanced the threonine metabolic pathways determine the deletion effects cobB in strain was produced pACYC184-thrABC vector, introducing the W3110_ △ cobB strain produced in Example 1 of this vector W3110_ △ cobB / pACYC184-thrABC was prepared.

Specifically, the vector pACYC184-thrABC was prepared in the following manner. The genomic DNA of E. coli KCCM 10541 (Korean Patent Registration No. 10-0576342), which is a strain for producing L-threonine, is used as a template and a polynucleotide of SEQ ID NOs: 13 and 14 is used as a primer, The obtained DNA fragment was isolated and purified, digested with HindIII enzyme, and further purified to prepare a thrABC DNA fragment. The pACYC184 vector was digested with HindIII enzyme, purified and prepared, and ligated with the thrABC DNA fragment to construct a pACYC184-thrABC vector. The thus produced vector was introduced via electroporation and the W3110 W3110_ △ cobB strains were each designated as W3110 / pACYC184-thrABC and W3110_ △ cobB / pACYC184-thrABC.

3. In a threonine producing strain cobB Production of defective strains

In this Example, a cobB- deficient strain was produced from a threonine producing strain in the same manner as in Example 1, using KCCM10541 (Korean Patent Registration No. 10-0576342), which is a threonine producing strain, as a parent strain , and named him as KCCM10541_ △ cobB.

Example 2. cobB  L-threonine productivity and NAD (H) level analysis of the deficient strains

1. Escherichia coli wild type strain and threonine metabolic pathway enhancing strain cobB  L-threonine productivity analysis of deficient strains

The recombinant microorganisms prepared in Examples 1 and 2 were cultured in an Erlenmeyer flask (250 ml) using the threonine titer medium shown in Table 1 to confirm L-threonine productivity improvement.

Composition Concentration (per liter) glucose 70 g KH ₂ PO ₄ 2 g (NH _{4) 2} SO ₄ 25 g MgSO ₄ .H ₂ O 1 g FeSO ₄ .H ₂ O 5 mg MnSO ₄ .H ₂ O 5 mg DL-methionine 0.15 g Yeast extract 2 g Calcium carbonate 30 g pH 6.8

The W3110, W3110_ΔcobB , W3110 / pACYC184-thrABC and W3110_ΔcobB / pACYC184-thrABC strains, which were cultured overnight in LB solid medium in an incubator (shaking incubator, J. Otec) at 33 ° C., One platinum was inoculated to the culture medium and then cultured for 48 hours in an incubator at 33 ° C and 200 rpm to analyze the productivity of L-threonine. The results are shown in Table 2.

Strain L-threonine (g / L) W3110 0.00 W3110_ΔcobB 0.01 W3110 / pACYC184-thrABC 1.42 W3110_ △ cobB / pACYC184-thrABC 1.89

As shown in Table 2, when the parent strain W3110 was cultured for 48 hours, L-threonine was not produced at all. However, the W3110_ΔcobB strain produced 0.01 g / L L-threonine Respectively. Leo also used for the non-enhanced biosynthesis W3110 / pACYC184-thrABC strain, 1.42g / L of the write Leo while producing non-, W3110_ △ cobB / pACYC184-thrABC strain to produce a non-used Leo of 1.89g / L It was confirmed that the threonine concentration produced increased by 33%.

2. In E. coli wild type strain cobB Of the strain defective NAD (H) level evaluation

In this embodiment, within the NAD (H) level of the cells were measured using a strain W3110_ △ cobB produced in one of the first embodiment.

Specifically, an NAD / NADH assay kit (EnzyChrom ^™ NAD + / NADH Assay Kit (ECND-100)) developed by Bioassay systems was used (Mol Cancer Ther., 2008, 7 (1): 110-120). W3110 and W3110_? CobB of Example 1 were cultured overnight in glucose-containing LB liquid medium used in Example 1, 2, contained in 250 ml Erlenmeyer flask. After culturing, the supernatant was removed by centrifugation, and the obtained cells were washed with ice-cold PBS. The cells were treated with NADH / NAD extraction buffer for 10 minutes at room temperature and low temperature and stirred to obtain NAD (H ) Exuded to the outside of the cell. Thereafter, the supernatant was separated again, and the assay buffer, reaction enzyme, ethanol, PMS, and MTT were mixed, and then OD ₅₆₅ was measured using an absorber to quantitate NAD (H). After repeating the above procedure three times, the average value of the experimental results was measured.

As a result, it was confirmed the intracellular NAD (H) levels in E. coli W3110_ △ cobB according to one embodiment hayeoteum increased by 10% compared to the wild type E. coli W3110 (Figure 1).

3. Threonine  From production strains cobB Of the strain defective Threonine Generation  evaluation

The exemplary Leo non yield used in the same way as in the one in Example 2 was measured for example in cobB gene prepared in 3 1 deficient master KCCM10541_ △ cobB and measuring the threonine-producing activity of the parent strain KCCM10541.

Strain L- Threonine (g / L) KCCM10541 30.4 KCCM10541_ΔcobB 36.1

As shown in Table 3, it was confirmed that the threonine concentration was increased about 20% in KCCM10541_ΔcobB as compared with the control group, KCCM10541.

4. Threonine  From production strains cobB Of the strain defective NAD (H) level evaluation

In order to evaluate the above Example 3 by cobB gene deletion master KCCM10541_ △ cobB the parent strain is within the NAD (H) level cells KCCM10541 prepared in 1 a NAD (H) level in the same way as 2 in the above Example 2 Respectively.

As a result, it was in E. coli KCCM10541_ △ cobB in accordance with one embodiment within the NAD (H) level, the cell can determine that it has increased by 14% compared to the parental strain of E. coli KCCM10541 (Fig. 2).

Korea Microorganism Conservation Center (overseas) KCCM11630P 20141205

<110> CJ corporation <120> Microorganism producing L-threonine and process for producing          L-threonine using the same <130> PN108388 <160> 14 <170> Kopatentin 2.0 <210> 1 <211> 279 <212> PRT <213> E. coli <400> 1 Met Leu Ser Arg Arg Gly His Arg Leu Ser Arg Phe Arg Lys Asn Lys   1 5 10 15 Arg Arg Leu Arg Glu Arg Leu Arg Gln Arg Ile Phe Phe Arg Asp Lys              20 25 30 Val Val Pro Glu Ala Met Glu Lys Pro Arg Val Leu Val Leu Thr Gly          35 40 45 Ala Gly Ile Ser Ala Glu Ser Gly Ile Arg Thr Phe Arg Ala Ala Asp      50 55 60 Gly Leu Trp Glu Glu His Arg Val Glu Asp Val Ala Thr Pro Glu Gly  65 70 75 80 Phe Asp Arg Asp Pro Glu Leu Val Gln Ala Phe Tyr Asn Ala Arg Arg                  85 90 95 Arg Gln Leu Gln Gln Pro Glu Ile Gln Pro Asn Ala Ala His Leu Ala             100 105 110 Leu Ala Lys Leu Gln Asp Ala Leu Gly Asp Arg Phe Leu Leu Val Thr         115 120 125 Gln Asn Ile Asp Asn Leu His Glu Arg Ala Gly Asn Thr Asn Val Ile     130 135 140 His Met His Gly Glu Leu Leu Lys Val Arg Cys Ser Gln Ser Gly Gln 145 150 155 160 Val Leu Asp Trp Thr Gly Asp Val Thr Pro Glu Asp Lys Cys His Cys                 165 170 175 Cys Gln Phe Pro Ala Pro Leu Arg Pro His Val Val Trp Phe Gly Glu             180 185 190 Met Pro Leu Gly Met Asp Glu Ile Tyr Met Ala Leu Ser Met Ala Asp         195 200 205 Ile Phe Ile Ala Ile Gly Thr Ser Gly His Val Tyr Pro Ala Ala Gly     210 215 220 Phe Val His Glu Ala Lys Leu His Gly Ala His Thr Val Glu Leu Asn 225 230 235 240 Leu Glu Pro Ser Gln Val Gly Asn Glu Phe Ala Glu Lys Tyr Tyr Gly                 245 250 255 Pro Ala Ser Gln Val Val Pro Glu Phe Val Glu Lys Leu Leu Lys Gly             260 265 270 Leu Lys Ala Gly Ser Ile Ala         275 <210> 2 <211> 840 <212> DNA <213> E. coli <400> 2 atgctgtcgc gtcggggtca tcggttaagt cgttttcgta aaaataaacg ccgcctgcgc 60 gagcgtttgc gtcagcgtat ttttttcaga gataaagtgg tgccggaagc aatggaaaaa 120 ccaagagtac tcgtactgac aggggcagga atttctgcgg aatcaggtat tcgtaccttt 180 cgcgccgcag atggcctgtg ggaagaacat cgggttgaag atgtggcaac gccggaaggt 240 ttcgatcgcg atcctgaact ggtgcaagcg ttttataacg cccgtcgtcg acagctgcag 300 cagccagaaa ttcagcctaa cgccgcgcat cttgcgctgg ctaaactgca agacgccctc 360 ggcgatcgct ttttgctggt gacgcagaat atcgacaacc tgcatgaacg cgcaggtaat 420 accaatgtga ttcatatgca tggggaactg ctgaaagtgc gttgttcaca aagtggtcag 480 gttctcgact ggacaggaga cgttacccca gaagataaat gccattgttg ccagtttccg 540 gcacccttgc gcccgcacgt agtgtggttt ggcgaaatgc cactcggcat ggatgaaatt 600 tatatggcgt tgtcgatggc cgatattttc attgccattg gcacatccgg gcatgtttat 660 ccggcggctg ggtttgttca cgaagcgaaa ctgcatggcg cgcacaccgt ggaactgaat 720 cttgaaccga gtcaggttgg taatgaattt gccgagaaat attacggccc ggcaagccag 780 gtggtgcctg agtttgttga aaagttgctg aagggattaa aagcgggaag cattgcctga 840                                                                          840 <210> 3 <211> 60 <212> DNA <213> Artificial Sequence <220> <223> foward primer for rmf promoter <400> 3 cagaggtacc caggaagccg cttctattgc cagaggtacc ccagcctgtt tacgatgatc 60                                                                           60 <210> 4 <211> 60 <212> DNA <213> Artificial Sequence <220> <223> reverse primer for rmf promoter <400> 4 gactgatatc gcctcgtttc cctcatactg gactgatatc gtgaccgata gtcagcgagt 60                                                                           60 <210> 5 <211> 64 <212> DNA <213> Artificial Sequence <220> <223> foward primer for pACYC184 <400> 5 atatcatatg taccgttcgt atagcataca ttatacgaag ttatctgccc tgaaccgacg 60 accg 64 <210> 6 <211> 65 <212> DNA <213> Artificial Sequence <220> <223> reverse primer for pACYC184 <400> 6 aattccatgg taccgttcgt ataatgtatg ctatacgaag ttatgcatca cccgacgcac 60 tttgc 65 <210> 7 <211> 70 <212> DNA <213> Artificial Sequence <220> <223> foward primer for pUCprmfmloxP <400> 7 tgcgtggtgc ggccttccta catctaaccg attaaacaac agaggttgct aggtgacact 60 atagaacgcg 70 <210> 8 <211> 70 <212> DNA <213> Artificial Sequence <220> <223> Reverse primer for pUCprmfmloxP <400> 8 cgcaaattca attaattgcg tccccttgca ggcctgataa gcgtagtgca ggtacccatc 60 agatccacta 70 <210> 9 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> foward primer for cobB deletion <400> 9 caatatccac tggtgatggg 20 <210> 10 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> Reverse primer for cobB deletion <400> 10 atttactacc cgcgaaccac 20 <210> 11 <211> 16 <212> DNA <213> Artificial Sequence <220> <223> Forward primer for confirmation of cobB deletion <400> 11 agggcgcacg ttgagc 16 <210> 12 <211> 16 <212> DNA <213> Artificial Sequence <220> <223> Reverse primer for confirmation of cobB deletion <400> 12 gactattgcc aatatg 16 <210> 13 <211> 30 <212> DNA <213> Artificial Sequence <220> <223> Forward primer for E. coli KCCM 10541 <400> 13 cgagaagctt agcttttcat tctgactgca 30 <210> 14 <211> 30 <212> DNA <213> Artificial Sequence <220> <223> Reverse primer for E. coli KCCM 10541 <400> 14 cgagaagctt attgagataa tgaatagatt 30

Claims (5)

An Escherichia genus microorganism having an ability to produce L-threonine, wherein the activity of the CobB protein is inactivated relative to the intrinsic activity. 2. The Escherichia genus microorganism according to claim 1, wherein the CobB protein comprises the amino acid sequence of SEQ ID NO: 1. 2. The Escherichia genus microorganism according to claim 1, wherein the CobB protein is encoded by the nucleotide sequence of SEQ ID NO: 2, having L-threonine producing ability. The Escherichia genus microorganism according to claim 1, wherein the Escherichia genus is Escherichia coli, L-threonine producing ability. Culturing the microorganism of any one of claims 1 to 4 in a medium; And
Threonine from said microorganism or medium. &Lt; RTI ID = 0.0 &gt; 21. &lt; / RTI &gt;

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