Cation efflux system CzcA/CusA/SilA/NccA/HelA/CnrA (IPR004763)

Short name: CzcA/CusA/SilA/NccA/HelA/CnrA

Overlapping homologous superfamilies


Family relationships


This family consists of the H+/heavy metal cation antiporters.

CzcA has a low cation transport activity for cobalt and is essential for the expression of cobalt, zinc and cadmium resistance.

CusA is a part of a cation efflux system that mediates resistance to copper and silver [PMID: 11399769, PMID: 12813074].

NccA is a component of the NCC cation-efflux system that confers resistance to nickel, cobalt and cadmium. It may form a membrane tunnel, which allows ion transport across the membrane.

SilA is a component of the sil cation-efflux system that confers resistance to silver. It may be part of a three-component cation/proton antiporter.

HelA is presumed to function with HelC and HelB in efflux of an unidentified substrate.

The products of the genes cnrA, cnrB, and cnrC are likely to form a membrane-bound protein complex catalyzing an energy-dependent efflux of Ni2+ and Co2+. The mechanism of action of the CnrCBA complex may be that of a proton/cation antiporter.

GO terms

Biological Process

GO:0006812 cation transport

Molecular Function

GO:0008324 cation transmembrane transporter activity

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.