%0 Journal Article
%T Bacillus subtilis SbcC protein plays an important role in DNA inter-strand cross-link repair
%A Judita Mascarenhas
%A Humberto Sanchez
%A Serkalem Tadesse
%A Dawit Kidane
%A Mahalakshmi Krisnamurthy
%A Juan C Alonso
%A Peter L Graumann
%J BMC Molecular Biology
%D 2006
%I BioMed Central
%R 10.1186/1471-2199-7-20
%X A deletion of the sbcC gene rendered Bacillus subtilis cells sensitive to DNA damage caused by Mitomycin C (MMC) or by gamma irradiation. The deletion of the sbcC gene in a recN mutant background increased the sensitivity of the single recN mutant strain. SbcC was also non-epistatic with AddAB (analog of Escherichia coli RecBCD), but epistatic with RecA. A deletion of the ykoV gene encoding the B. subtilis Ku protein in a sbcC mutant strain did not resulted in an increase in sensitivity towards MMC and gamma irradiation, but exacerbated the phenotype of a recN or a recA mutant strain. In exponentially growing cells, SbcC-GFP was present throughout the cells, or as a central focus in rare cases. Upon induction of DNA damage, SbcC formed 1, rarely 2, foci on the nucleoids. Different to RecN protein, which forms repair centers at any location on the nucleoids, SbcC foci mostly co-localized with the DNA polymerase complex. In contrast to this, AddA-GFP or AddB-GFP did not form detectable foci upon addition of MMC.Our experiments show that SbcC plays an important role in the repair of DNA inter-strand cross-links (induced by MMC), most likely through HR, and suggest that NHEJ via Ku serves as a backup DNA repair system. The cell biological experiments show that SbcC functions in close proximity to the replication machinery, suggesting that SbcC may act on stalled or collapsed replication forks. Our results show that different patterns of localization exist for DNA repair proteins, and that the B. subtilis SMC proteins RecN and SbcC play distinct roles in the repair of DNA damage.All organisms need to ensure the integrity of their genome. A major threat are inter-strand cross-links and double strand breaks (DSBs) in the DNA that can cause cell death or cellular transformation. The repair of inter-strand cross-links appears to be achieved via two pathways, including proteins involved in nucleotide excision repair, and DNA polymerase II or proteins mediating homologous reco
%U http://www.biomedcentral.com/1471-2199/7/20