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Escherichia coli DNA gyrase: Genetic analysis of gyr A and gyr B mutations responsible for thermosensitive enzyme activity
Author(s) -
Oram Mark,
Kuroda Reiko,
Fisher L.Mark
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)81410-n
Subject(s) - escherichia coli , dna gyrase , genetics , dna , enzyme , biology , microbiology and biotechnology , chemistry , gene , biochemistry
Escherichia coli gyr A 43 and gyr B 203 alleles conferring temperature‐sensitive (ts) growth encoded Gly 751 → Asp and Pro 171 → 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 Pro 171 → 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.