Table 3.

List of putative specific transporters for heavy-metals present in representative rhodococcal species.

Substrate	Transporter	Family	Species (No. of transporters)	Gene location (No. of transporters)
Arsenite	ArsA	Arsenite-antimonite (ArsAB) efflux family	R. equi (1)	C
			R. erythropolis (4)	C (3) + P (1)
			R. jostii (3)	C
			R. opacus (4)	C
	ArsB		R. equi (1)	C
			R. erythropolis (1)	C
			R. jostii (1)	C
			R. opacus (1)	C
	UN	Arsenical resistance-3 (ACR3) family	R. equi (1)	C
			R. erythropolis (2)	C (1)+ P (1)
			R. jostii (1)	C
			R. opacus (3)	C
Cadmium	UN	P-type ATPase	R. jostii (1)	C
Cobalt	UN	ATP-Binding cassette (ABC)	R. equi (8)	C
			R. erythropolis (6)	C
			R. jostii (5)	C
			R. opacus (5)	C
Cobalt/Zinc/Cadmium	UN	P-type ATPase	R. equi (4)	C
			R. erythropolis (5)	C (3) + P (2)
			R. jostii (5)	C
			R. opacus (3)	C

UN, unnamed; C, chromosome; P, plasmid.