Table 2.

Transporters used as the import system in bioaccumulation studies.

Major transporter class	Superfamily	Family	Transporter name	Organism	Target
Channels 1.A	Major Intrinsic Protein 1.A.8	/	GlpF/homologs	Escherichia coli, Corynebacterium diptheriae, Streptomyces coelicolor	As3+
			Fps1	Saccharomyces cerevisiae	As3+
	Mer 1.A.72	/	MerT/P	Serratia marcescens, Pseudomonas K-62, Pseudomonas K-12	Hg
Secondary Carriers 2.A	Transporter-Opsin-G protein-coupled receptors*	NiCoT 2.A.52	NixA/homologs	Helicobacter pylori, Novosphingobium aromaticivorans, Rhodopseudomonas palustris	Ni/Co
				Staphylococcus aureus	Ni/Co
	Major Facilitator 2.A.1	Sugar Porter 2.A.1.1	Hxt7	Saccharomyces cerevisiae	As4+
		${\text{PO}}_4^{2-}$:H+ Symporter 2.A.1.9	Pho84	Saccharomyces cerevisiae	As4+
Primary active transporters 3.A	P-type ATPase 3.A.3	/	MntA	Lactobacillus plantarum	Cd
			cdtB/ lp_3327	Lactobacillus plantarum	Cd
			TcHMA3	Thlaspi caerulescens	Cd
			CopA	Enterobacter hirae	Cu

Transport classification database (TCDB) identifiers are indicated by names where appropriate. Some transporters belong to branches within their superfamily, indicated under the Family column.

^*A superfamily comprised of transporters from different families.