title: Contribution of the ATP binding site of ParE to susceptibility to novobiocin and quinolones in Streptococcus pneumoniae.
abstract: In Streptococcus pneumoniae, an H103Y substitution in the ATP binding site of the ParE subunit of topoisomerase IV was shown to confer quinolone resistance and hypersensitivity to novobiocin when associated with an S84F change in the A subunit of DNA gyrase. We reconstituted in vitro the wild-type topoisomerase IV and its ParE mutant. The ParE mutant enzyme showed a decreased activity for decatenation at subsaturating ATP levels and was more sensitive to inhibition by novobiocin but was as sensitive to quinolones. These results show that the ParE alteration H103Y alone is not responsible for quinolone resistance and agree with the assumption that it facilitates the open conformation of the ATP binding site that would lead to novobiocin hypersensitivity and to a higher requirement of ATP.
authors.affiliation: INSERM E0004, Laboratoire de Recherche Moléculaire sur les Antibiotiques, 15, rue de l'Ecole de Médecine, Université Paris VI, 75270 Paris Cedex 06, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Dupont
authors.forename: Alexandra
authors.initials: A
authors.lastname: Aubry
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Cambau
authors.forename: Laurent
authors.initials: L
authors.lastname: Gutmann
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001665:Binding Sites; D027081:DNA Gyrase / Q000235:genetics / Q000378:metabolism; D027101:DNA Topoisomerase IV / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D009154:Mutation; D009675:Novobiocin / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D015363:Quinolones / Q000494:pharmacology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D015363:Quinolones; D009675:Novobiocin; D000255:Adenosine Triphosphate; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase