PCR random mutagenesis into Escherichia coli serine acetyltransferase: isolation of the mutant enzymes that cause overproduction of L‐cysteine and L‐cystine due to the desensitization to feedback inhibition

FEBS Letters

Takagi, Hiroshi¹  Nakamori, Shigeru¹  Kobayashi, Shin-ichiro¹  Kobayashi, Chitose¹ 

[1] Department of Bioscience, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka-cho, Fukui 910-1195, Japan

关键词: L-Cysteine overproduction;    Feedback inhibition;    Random mutagenesis;    Serine acetyltransferase;   

DOI  :  10.1016/S0014-5793(99)00679-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

PCR random mutagenesis in the cysE gene encoding Escherichia coli serine acetyltransferase was employed to isolate the mutant enzymes that, due to a much less feedback inhibition by L-cysteine, cause overproduction of L-cysteine and L-cystine in the recombinant strains. The L-cysteine auxotrophic and non-utilizing E. coli strain was transformed with plasmids having the altered cysE genes. Then, several transformants overproducing L-cysteine were selected by detecting the halo formation of the L-cysteine auxotroph. The production test of amino acids and analysis of the catalytic property on the mutant enzymes suggest that the carboxy-terminal region of serine acetyltransferase plays an important role in the desensitization to feedback inhibition and the high level production of L-cysteine and L-cystine.

【 授权许可】

Unknown