title: A bacitracin-resistant Bacillus subtilis gene encodes a homologue of the membrane-spanning subunit of the Bacillus licheniformis ABC transporter.
abstract: Bacitracin is a peptide antibiotic nonribosomally produced by Bacillus licheniformis. The bcrABC genes which confer bacitracin resistance to the bacitracin producer encode ATP binding cassette (ABC) transporter proteins, which are hypothesized to pump out bacitracin from the cells. Bacillus subtilis 168, which has no bacitracin synthesizing operon, has several genes homologous to bcrABC. It was found that the disruption of ywoA, a gene homologous to bcrC, resulted in hypersensitivity to bacitracin. Resistance to other drugs such as surfactin, iturin A, vancomycin, tunicamycin, gramicidin D, valinomycin and several cationic dyes were not changed in the ywoA disruptant. Spontaneous bacitracin-resistant mutants (Bcr-1 and -2) isolated in the presence of bacitracin have a single base substitution from A to G in the ribosome binding region. Northern hybridization analysis and determination of the expression of ywoA-LacZ transcriptional fusion gene revealed that the transcription of the ywoA gene was dependent on extracytoplasmic function (ECF) sigma factors sigma(M) and sigma(X). Preincubation of wild-type cells in the presence of a low concentration of bacitracin induced increased resistance to bacitracin about two- to threefold, although the mechanism of this induction has not yet been elucidated. It has been reported that a commercially available bacitracin is a mixture of several components and also contains impurity. Bacitracin A was purified by reverse phase high-performance liquid chromatography (HPLC). Similar results were obtained with bacitracin A as those with crude bacitracin, indicating that contaminating substances were not responsible for the results obtained in this study.
authors.affiliation: Department of Molecular Biolog, School of Health Sciences, Kyorin University, 476 Miyashita, Hachioji, Tokyo 192-0005, Japan. ohkir@kyorin-u.ac.jp
authors.forename: Reiko
authors.initials: R
authors.lastname: Ohki
authors.forename: Kozue
authors.initials: K
authors.lastname: Tateno
authors.forename: Youji
authors.initials: Y
authors.lastname: Okada
authors.forename: Haruo
authors.initials: H
authors.lastname: Okajima
authors.forename: Kei
authors.initials: K
authors.lastname: Asai
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Sadaie
authors.forename: Makiko
authors.initials: M
authors.lastname: Murata
authors.forename: Toshiko
authors.initials: T
authors.lastname: Aiso
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001407:Bacillus / Q000235:genetics / Q000378:metabolism*; D001412:Bacillus subtilis / Q000187:drug effects* / Q000235:genetics; D001414:Bacitracin / Q000378:metabolism / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D017353:Gene Deletion; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017385:Sequence Homology
chemical_list: D018528:ATP-Binding Cassette Transporters; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C121796:bacitracin permease; D001414:Bacitracin