New tmk gene of Coryneform bacteria, useful when suppressed, for increasing fermentative production of L-amino acids, encodes a thymidylate kinase

摘要

Isolated polynucleotide (I) from Coryneform bacteria that represents the tmk gene is: (i) 70% identical with a polynucleotide that encodes a 203 amino acid (aa) S(2), reproduced; (ii) encodes a polypeptide at least 70% identical with (S2); (iii) the complement of (i) or (ii), or (iv) contains at least 15 consecutive nucleotides from (i)-(iii). Encoded polypeptides preferably have the activity of a thymidylate kinase. Independent claims are also included for the following: (1) Coryneform bacteria in which activity of the tmk gene has been reduced, especially switched off; (2) a vector pXK99E; Escherichia coli DH5 alpha mer/pXK99Etmk, DSM14439; (3) fermentative production of L-aa, especially L-lysine, by growing bacteria of (1); and (4) Coryneform bacteria containing a vector that carries a fragment, of at least 15 consecutive nucleotides (nt), from (I).