ESCHERICHIA-COLI DNA GYRASE - GENETIC-ANALYSIS OF GYRA AND GYRB MUTATIONS RESPONSIBLE FOR THERMOSENSITIVE ENZYME-ACTIVITY

作者：ORAM M; KURODA R; FISHER LM

来源：FEBS Letters, 1992, 312(1): 61-65.

DOI：10.1016/0014-5793(92)81410-N

• DNA SUPERCOILING
• DNA GYRASE
• TEMPERATURE-SENSITIVE MUTATION
• NALIDIXIC ACID RESISTANCE
• ESCHERICHIA-COLI

Escherichia coli gyrA43 and gyrB203 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 gyrA43 allele was genetically dominant over a chromosomal quinolone-resistant gyrA gene at 30-degrees-C but not at 42-degrees-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 supercoiling. These data are discussed in regard to recently described gyrA(ts) mutations that affect the control of chromosome segregation.

• 出版日期1992-11-2