Microcin H47 System: An Escherichia coli Small Genomic Island with Novel Features

摘要: Genomic islands are DNA regions containing variable genetic information related to secondary metabolism. Frequently, they have the ability excise from and integrate into replicons through site-specific recombination. Thus, usually flanked by short direct repeats that act as attachment sites, contain genes for an integrase excisionase which carry out exchange. These mobility events would be at basis of horizontal transfer genomic among bacteria. Microcin H47 is a ribosomally-synthesized antibacterial peptide belongs group chromosome-encoded microcins. The 13 kb-genetic system responsible its production resides in chromosome Escherichia coli strain extensive imperfect repeats. In this work, both excision integration microcin were experimentally detected. analyses mainly performed E. K12 cells carrying cloned multicopy plasmid. As expected recombination event, exchange also occurred context deficient homologous sequence sites resulting hybrid between sequences Unexpectedly, different appeared resulted four segments identity Genes encoding trans-acting proteins shown absent system. Therefore, should provided remaining context, not only but cells, where occurred. Moreover, survey data banks revealed widely spread strains. It concluded small island –H47 island- employ parasitic strategy mobility.