L-methionine producing microorganism to which protein encoded by foreign
An L-methionine-producing microorganism into which a met Z gene is introduced and a method of producing L-methionine using the same.
1 . A method of producing L-methionine, the method comprising culturing an L-methionine producing microorganism of the genus Corynebacterium , into which a protein encoded by a foreign met Z gene is introduced, in a medium containing thiosulfate, thereby producing L-methionine, wherein the protein has O-acylhomoserine transsulfurase activity.
2 . The method of producing L-methionine of claim 1 , wherein the protein is derived from Chromobacterium violaceum, Hyphomonas neptunium , or Rhodobacter sphaeroides.
3 . The method of producing L-methionine of claim 1 , wherein the protein has at least 90% sequence identity to SEQ ID NOS: 60, 61, or 62.
4 . The method of producing L-methionine of claim 1 , wherein the microorganism includes one or more genetic modifications selected from the group consisting of attenuation or inactivation of activity of cystathionine gamma synthase; attenuation or inactivation of activity of O-acetylhomoserine sulfhydrylase; attenuation or inactivation of activity of methionine-cysteine biosynthesis repressor protein; enhancement of activity of methionine synthase; and enhancement of activity of sulfite reductase,
wherein the enhancement of activity of the polypeptide or protein is achieved by:
1) a method of increasing the intracellular copy number of a gene or polynucleotide encoding the polypeptide or protein;
2) a method of replacing a gene expression regulatory region on the chromosome encoding the polypeptide or protein with a sequence having a strong activity;
3) a method of modifying a nucleotide sequence of a start codon or 5′-UTR region of the polypeptide or protein;
4) a method of modifying a polynucleotide sequence on the chromosome to increase the activity of the polypeptide or protein;
5) a method of introducing a foreign polynucleotide exhibiting the activity of the polypeptide or protein, or introducing a variant polynucleotide by codon-optimization of the polynucleotide; or
6) a combination of two or more selected from 1) to 5) above,
wherein the inactivation or attenuation of the activity of the protein is achieved by:
1) a method of deleting all or a part of the gene encoding the protein;
2) a method of modifying the expression regulatory region (or expression regulatory sequence) such that the expression of the gene encoding the protein is decreased;
3) a method of modifying the gene sequence encoding the protein such that the protein activity is removed or weakened;
4) a method of introducing an antisense oligonucleotide that binds complementarily to a transcript of the gene encoding the protein;
5) a method of adding a complementary sequence to the Shine-Dalgarno sequence upstream of the Shine-Dalgarno sequence of the gene encoding the protein to form a secondary structure, thereby inhibiting the ribosomal binding;
6) a reverse transcription engineering (RTE) method of adding a promoter at the 3′ terminus of an open reading frame (ORF) of the polynucleotide sequence of the gene encoding the protein so as to be reversely transcribed; or
7) a combination of two or more selected from 1) to 6) above.
5 . The method of producing L-methionine of claim 1 , wherein the microorganism is Corynebacterium glutamicum.
6 . The method of producing L-methionine of claim 1 , comprising recovering L-methionine from the microorganism or medium.
7 . The method of producing L-methionine of claim 1 , wherein homolanthionine production is reduced.