RecX alone, or in concert with RecO or RecF, plays an important role in chromosomal and plasmid transformation.

The metB5 locus contains a single point mutation.aThe yield of met+ transformants (SB19 DNA, chromosomal transformation) andbkanamycin resistant transformants (pUB110, plasmid transformation) was corrected for DNA uptake and cell viability, and the values obtained normalized relative to that of the rec+ strain, taken as 100. Between parentheses is included the number of transformants/cell.cThe transformation frequencies of rec+, recF15, ΔrecR, ΔrecO, recX342 (previously termed recH342), recX342 ΔrecR, recX342 recF15, recX342 ΔrecO, recX342 ΔrecR and ΔrecA cells were reported elsewhere [13], [15], [16], [52] and determined here for direct comparison. The results are the average of at least three independent experiments and are within a 10% standard error.