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Analysis of the NH 2 ‐Terminal 87th Amino Acid of Escherichia coli GyrA in Quinolone‐Resistance
Author(s) -
Yonezawa Minoru,
Takahata Masahiro,
Banzawa Naoko,
Matsubara Nobuyuki,
Watanabe Yasuo,
Narita Hirokazu
Publication year - 1995
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1995.tb02236.x
Subject(s) - dna gyrase , escherichia coli , quinolone , biology , mutant , genetics , amino acid , mutagenesis , mutation , gene , microbiology and biotechnology , antibiotics
The functional contributions of amino acid residue Asp87 of Escherichia coli gyrase A protein (GyrA) was analyzed by site‐directed mutagenesis. We generated a series of mutants, in which Asp87 of GyrA was changed to Ala, Val, Phe, Asn, Ser, and Lys. By genetic analysis of gyrA genes in a gyrA temperature‐sensitive (Ts) background, it was shown that all these mutations caused the quinolone‐resistance. These results indicate that the 87th amino acid of E. coli GyrA must have negative charge in expressing the phenotype of quinolone sensitivity. These findings also suggest that the carboxyl group of Asp87 may interact with quinolone drugs.