Exonuclease requirements for recombination of λ-phage in recD mutants of Escherichia coli

Abstract

Recombination of λ red gam phage in recD mutants is unaffected by inactivation of RecJ exonuclease. Since nucleases play redundant roles in E. coli, we inactivated several exonucleases in a recD mutant and discovered that 5′-3′ exonuclease activity of RecJ and exonuclease VII is essential for l-recombination, whereas exonucleases of 3′-5′ polarity are dispensable. The implications of the presented data on current models for recombination initiation in E. coli are discussed. Copyright © 2006 by the Genetics Society of America.