RESUMO
Resolution of chromosome dimers, by site-specific recombination between dif sites, is carried out in Escherichia coli by XerCD recombinase in association with the FtsK protein. We show here that a variety of altered FtsK polypeptides, consisting of the N-terminal (cell division) domain alone or with deletions in the proline-glutamine-rich part of the protein, or polypeptides consisting of the C-terminal domain alone are all unable to carry out dif recombination. Alteration of the putative nucleotide-binding site also abolishes the ability of FtsK to carry out recombination between dif sites.
Assuntos
Cromossomos Bacterianos , Escherichia coli/genética , Proteínas de Membrana/metabolismo , Recombinação Genética , Proteínas de Escherichia coli , Deleção de SequênciaRESUMO
Deletion of ftsK results in the inhibition of cell division, but this inhibition can be reversed by a plasmid carrying only the first approximately 17% of ftsK. The division block can be suppressed in most mutants by deletion of dacA, which codes for the D-alanine:D-alanine carboxypeptidase PBP5, or in all mutants by overexpression of ftsN. Overexpression of ftsK inhibits cell division and the formation of FtsZ rings. This division block is not due to the induction of either the SOS or the heat shock regulons.
