The recombination genes addAB are not restricted to gram-positive bacteria: genetic analysis of the recombination initiation enzymes RecF and AddAB in Rhizobium etli.

ABSTRACT: Single-strand gaps (SSGs) and double-strand breaks (DSBs) are the major initiation sites for recombination. In bacteria, the SSGs are repaired by RecFOR, while the DSBs are processed by RecBCD in gram-negative bacteria and AddAB in gram-positive bacteria. Unexpectedly, instead of recBCD genes, the addAB genes were found in members of the alpha-proteobacteria group (gram negative). Taking Rhizobium etli as a model, the role of recF and addAB genes in homologous recombination and repair of damaged DNA was evaluated. Inactivation of either recF or addA provoked strong sensitivity to UV radiation and mitomycin C, while an additive effect was observed in the recF-addA mutant. The DSBs generated by nalidixic acid caused low viability only in the addA mutant. The recombination frequency of large

SUBMITTER: Zuniga-Castillo J 

PROVIDER: S-EPMC529079 | biostudies-literature | 2004 Dec

REPOSITORIES: biostudies-literature