UvrD permits ICEBs1 replication in a pcrA-defective strain.

Induction of ICEBs1 gene expression was carried out by overproduction of RapI from amyE::{Pxyl-rapI spc} for two hours followed by mating as described in Materials and Methods. Data presented are averages from two experiments ± standard deviation. Wild type and all derivates of ICEBs1 contained Δ(rapI-phrI)::kan. All strains were also thrC mutants, with either thrC::cat or E. coli uvrD cloned and integrated into thrC (thrC::Pspank-uvrD mls).