Escherichia coli DNA gyrase: Genetic analysis of gyr A and gyr B mutations responsible for thermosensitive enzyme activity

FEBS Letters

Kuroda, Reiko²  Oram, Mark¹  Fisher, L.Mark¹ 

[1] Molecular Genetics Group, Department of Cellular and Molecular Sciences, St. George's Hospital Medical School, University of London, UK;Department of Chemistry, College of Arts and Sciences, University of Tokyo, Komaba, Tokyo 153, Japan

关键词: DNA supercoiling;    DNA gyrase;    Temperature-sensitive mutation;    Nalidixic acid resistance;    Escherichia coli;   

DOI  :  10.1016/0014-5793(92)81410-N

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Escherichia coli gyr A 43 and gyr B 203 alleles conferring temperature-sensitive (ts) growth encoded Gly⁷⁵¹ → Asp and Pro¹⁷¹ → ser substitutions in the DNA gyrase A and B subunits, respectively. A plasmid-borne gyr A 43 allele wasg genetically dominant over a chromosomal quinolone-resistant gyr A gene at 30°C but not at 42°C. These results and others confirm the ts phenotype of the mutation, the first to be identified in the C-terminal DNA binding/complex stabilizing domain of gyrase A protein. By contrast, the Pro¹⁷¹ → Ser mutation is located near the ATP-binding site of gyrase B protein and could interfere with energy coupling during DNA supercooling. These data are discussed in regard to recently described gyr A (ts) mutations that affect the control of chromosome segregation.

【 授权许可】

Unknown