| Literature DB >> 11292337 |
J G Heddle1, S J Blance, D B Zamble, F Hollfelder, D A Miller, L M Wentzell, C T Walsh, A Maxwell.
Abstract
Microcin B17 is a 3.1-kDa bactericidal peptide; the putative target of this antibiotic is DNA gyrase. Microcin B17 has no detectable effect on gyrase-catalysed DNA supercoiling or relaxation activities in vitro and is unable to stabilise DNA cleavage in the absence of nucleotides. However, in the presence of ATP, or the non-hydrolysable analogue 5'-adenylyl beta,gamma-imidodiphosphate, microcin B17 stabilises a gyrase-dependent DNA cleavage complex in a manner reminiscent of quinolones, Ca(2+), or the bacterial toxin CcdB. The pattern of DNA cleavage produced by gyrase in the presence of microcin B17 is different from that produced by quinolones and more closely resembles Ca(2+)-mediated cleavage. Several gyrase mutants, including well-known quinolone-resistant mutants, are cross resistant to microcin-induced DNA cleavage. We suggest that microcin exerts its effects through a mechanism that has similarities to those of both the bacterial toxin CcdB and the quinolone antibacterial agents. Copyright 2001 Academic Press.Entities:
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Year: 2001 PMID： 11292337 DOI： 10.1006/jmbi.2001.4562
Source DB: PubMed Journal: J Mol Biol ISSN： 0022-2836 Impact factor: 5.469