TABLE 3.

Predicted and verified RcGTA recipient capability genes^e

R. capsulatus genee	Annotation	Predicted/verified function(s) and/or characteristic(s) of gene product	WT/ΔctrA ratio		Predicted TMS (n)	Phenotype of mutant(s)
			Stationarya	Logb		Transformationc	RcGTA recipient capabilityd
rcc00197	comF	Unknown; required for DNA transport from periplasm to cytoplasm	3.23	5.35	1	Not detectable	Unknown
rcc00460	comM	Unknown; putative ATPase and helicase-like domains	2.91	1.89	0	Variable; 0– to 300-fold reduction	Unknown
rcc02362	comEC-rec2	Integral membrane protein; transports DNA from periplasm to cytoplasm	4.88	2.67	6	Not detectable	Unknown
rcc03098	dprA	Recombination mediator; loads RecA into ssDNA	9.38	3.75	0	Not detectable	Not detectable
rcc01751	recA	Recombination protein A; RecA; DNA repair and homologous recombination	1.47	1.22	0	Not detectable	Not detectable
rcc01663	ctrA	Cell cycle transcriptional regulator CtrA; regulates transcription of RcGTA and com genes	0.94	1.04	0	Unknown	Not detectable

^aRatio of WT to ΔctrA microarray expression values for cells grown to the exponential phase of growth.

^bRatio of WT to ΔctrA microarray gene expression values for cells grown to the stationary phase of growth.

^cA 10⁷-fold reduction in transformation was used as the limit of detection in other species.

^dA 10⁶-fold reduction in recipient capability was used as the limit of detection in R. capsulatus.

^eShown are predicted and verified RcGTA recipient capability genes, their annotations, predicted or verified functions, expression levels in the ΔctrA mutant versus the wild type in both stationary and log phases, the numbers of predicted transmembrane segments (TMS), the phenotypes in natural transformation systems, and the phenotypes resulting from mutations in these genes in natural transformation systems and in RcGTA recipient capability. Microarray expression values are derived from data reported in reference 61, and ΔdprA, ΔrecA, and ΔctrA mutant phenotypes were reported previously by Brimacombe et al. (13).