Table 1.

The role of RecU in plasmid transformation is superseded in the recA context.

Straina	Relevant genotype	Normalized chromosomal transformation	Normalized plasmid transformation
BG214	rec+	100 (4.1 × 105)	100 (9.1 × 103)
BG190	ΔrecA	<0.01	98 ± 2
BG1163	ΔdprA	1.3 ± 0.4	2.2 ± 0.5
BG855	ΔrecX	0.46 ± 0.2	1.6 ± 0.2
BG855	ΔrecU	51 ± 2.0	2.6 ± 0.6
BG703	ΔruvAB	78 ± 7	37 ± 5
BG651	ΔrecU ΔrecA	<0.01	44 ± 3
BG1147	ΔrecX ΔrecA	<0.01	55 ± 8
BG1081	ΔrecU ΔrecX	<0.01	<0.01
BG1609	ΔrecU ΔdprA	0.8 ± 0.4	0.9 ± 0.3
BG1291	ΔdprA ΔrecA	<0.01	0.4 ± 0.1

^aAll strains are isogenic with BG214 (rec⁺). The genotype of the parental strain is trpCE metA5 amyE1 ytsJ1 rsbV37 xre1 xkdA1 att^SPβ att^ICEBs1. Competent B. subtilis cells auxotrophic for methionine were transformed with 0.1 μg of chromosomal DNA from the prototroph SB19 strain to met⁺or with the pUB110 plasmid DNA to Nm^R. The yield of met⁺(chromosomal transformation) and Nm^R transformants (plasmid pUB110 transformation) was corrected for DNA uptake and cell viability, and the values obtained were normalized relative to that of the rec⁺strain, recorded as 100 (in parentheses, number of transformants per 0.1 μg DNA). Results are shown as mean of at least seven independent experiments.