Mutations in the proteolytic domain of Escherichia coli protease Lon impair the ATPase activity of the enzyme

FEBS Letters

Starkova, Natalie N¹  Koroleva, Ekaterina P¹  Ginodman, Lev M¹  Rumsh, Lev D¹  Rotanova, Tatyana V¹ 

[1] Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya st. 16/10, 117871 Moscow, Russia

关键词: Adenosine triphosphate-dependent proteolysis;    Protease Lon;    Active site;    Site-directed mutagenesis;    Escherichia coli;   

DOI  :  10.1016/S0014-5793(98)00012-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Conserved residues of the proteolytic domain of Escherichia coli protease Lon, putative members of the classic catalytic triad (H665, H667, D676, and D743) were identified by comparison of amino acid sequences of Lon proteases. Mutant enzymes containing substitutions D676N, D743N, H665Y, and H667Y were obtained by site-directed mutagenesis. The mutant D743N retained the adenosine triphosphate (ATP)-dependent proteolytic activity, thereby indicating that D743 does not belong to the catalytic site. Simultaneously, the mutants D676N, H665Y, and H667Y lost the capacity for hydrolysis of protein substrates. The ATPase activity of these three mutants was decreased by more than an order of magnitude, which suggests a close spatial location of the ATPase and proteolytic active sites and their tight interaction in the process of protein degradation.

【 授权许可】

Unknown