bleomycin sensitivity in escherichia coli is medium-dependent博来霉素敏感性在medium-dependent大肠杆菌.pdfVIP

Bleomycin Sensitivity in Escherichia coli is Medium- Dependent Tao Xu, William Brown, Martin G. Marinus* Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America Abstract Bleomycin (BLM) is a glycopeptide antibiotic and anti-tumor agent that targets primarily the furanose rings of DNA and in the presence of ferrous ions produces oxidative damage and DNA strand breaks. Escherichia coli cells growing in broth medium and exposed to low concentrations of BLM contain double-strand breaks and require homologous recombination to survive. To a lesser extent, the cells also require the abasic (AP) endonucleases associated with base excision repair, presumably to repair oxidative damage. As expected, there is strong induction of the SOS system in treated cells. In contrast, E. coli cells growing in glucose or glycerol minimal medium are resistant to the lethal action of BLM and do not require either homologous recombination functions or AP-endonucleases for survival. DNA ligase activity, however, is needed for cells growing in minimal medium to resist the lethal effects of BLM. There is weak SOS induction in such treated cells. Citation: Xu T, Brown W, Marinus MG (2012) Bleomycin Sensitivity in Escherichia coli is Medium-Dependent. PLoS ONE 7(3): e33256. doi:10.1371/ journal.pone.0033256 Editor: Michael R. Volkert, University of Massachusetts Medical School, United States of America Received December 6, 2011; Accepted February 6, 2012; Published March 15, 2012 Copyright: 2012 Xu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.