Nickel ABC transporter, substrate-binding protein NikA (IPR011980)

Short name: NikA_ABC_Ni-bd

Overlapping homologous superfamilies


Family relationships


Members of this family are periplasmic nickel-binding proteins of nickel ABC transporters [PMID: 7867647, PMID: 7934931]. Nickel is bound specifically, albeit weakly, through water molecules positioned in the binding site. The amino acids whose side chains line the binding site include Tyr-44, Met-49, Trp-122, Arg-159, Trp-420, and Tyr-424 (numbering based on the precursor sequence of Escherichia coli NikA) with the Arg contributing a hydrogen bond indirectly through a water molecule [PMID: 12960164]. NikA may serve as a heme chaperone as well as a periplasmic nickel-binding protein [PMID: 17411076].

Bacterial high affinity transport systems are involved in active transport of solutes across the cytoplasmic membrane. Most of the bacterial ABC (ATP-binding cassette) importers are composed of one or two transmembrane permease proteins, one or two nucleotide-binding proteins and a highly specific periplasmic solute-binding protein. In Gram-negative bacteria the solute-binding proteins are dissolved in the periplasm, while in archaea and Gram-positive bacteria, their solute-binding proteins are membrane-anchored lipoproteins [PMID: 8003968, PMID: 18310026].

GO terms

Biological Process

GO:0015675 nickel cation transport

Molecular Function

GO:0020037 heme binding
GO:0016151 nickel cation binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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