• 제목/요약/키워드: site-specific mutagensis

검색결과 1건 처리시간 0.015초

Escherichia coli $\gamma$-Glutamylcysteine Synthetase의 아미노산 치환 효과 (Effect of Amino Acid Substitutions of Escherichia Coli $\gamma$-Glutamylcysteine Synthetase)

  • 남용석;김중수;곽준혁;박영인;이세영
    • 미생물학회지
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    • 제29권5호
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    • pp.278-283
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    • 1991
  • Two amino acid residues ($Ala^{494}$ and $Ser^{495}$ of E. coli .gamma.-glutamylcysteine synthetase have been investigated whether they are the site of feedback inhibition by site specific mutagenesis. Single substitution of $serine^{495}$ (S495F), and double substitutions of alanine$^{494}$ and $serine^{495}$ (A494G-S495F) resulted in the inactivation of the .gamma.-glutamylcysteine synthetase activity. Substitution of $alanine^{494}$ with $glycine^{494}$ resulted in a higher level of feedback inhibition. These results suggest that $serine^{495}$ in .gamma.-glutamylcysteine synthetase is required for its catalytic acitvity and $alanine^{494}$ is presumably related to the feeback inhibition site.

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