title: Influence of lineage-specific amino acid dimorphisms in GyrA on Mycobacterium tuberculosis resistance to fluoroquinolones.
abstract: We conducted in vitro DNA supercoiling assays, utilizing recombinant DNA gyrases,  to elucidate the influence of the lineage-specific serine or threonine residue at position 95 of  GyrA on fluoroquinolone resistance in Mycobacterium tuberculosis. There was little effect of the  GyrA-Ala74Ser amino acid substitution on activity of the GyrA-Ser95 gyrase, while activity of the  GyrA-Asp94Gly-Ser95 gyrase was reduced. These findings were in striking contrast to previous reports  analyzing GyrA with Thr95 and suggest an important impact of the amino acid in the development of  fluoroquinolone resistance.
authors.affiliation: Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.forename: Chie
authors.initials: C
authors.lastname: Nakajima
authors.forename: Youn Uck
authors.initials: YU
authors.lastname: Kim
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D019943:Amino Acid Substitution; D027081:DNA Gyrase / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004278:DNA, Superhelical / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004789:Enzyme Activation; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D024841:Fluoroquinolones / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000235:genetics / Q000378:metabolism; D013912:Threonine / Q000235:genetics / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004278:DNA, Superhelical; D024841:Fluoroquinolones; D011994:Recombinant Proteins; D013912:Threonine; D012694:Serine; D027081:DNA Gyrase