Solute-binding protein family 5 domain (IPR000914)

Short name: SBP_5_dom

Overlapping homologous superfamilies


Domain relationships



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].

On the basis of sequence similarities, the vast majority of these solute-binding proteins can be grouped [PMID: 8336670] into eight families or clusters, which generally correlate with the nature of the solute bound. This entry represents a domain found in the solute-binding protein family 5.

Family 5 members include:

  • Periplasmic oligopeptide-binding proteins (oppA) of Gram-negative bacteria and homologous lipoproteins in Gram-positive bacteria (oppA, amiA or appA)
  • Periplasmic dipeptide-binding proteins of Escherichia coli (dppA) and Bacillus subtilis (dppE)
  • Periplasmic murein peptide-binding protein of E. coli (mppA)
  • Periplasmic peptide-binding proteins sapA of E. coli, Salmonella typhimurium and Haemophilus influenzae
  • Periplasmic nickel-binding protein (nikA) of E. coli
  • Haem-binding lipoprotein (hbpA or dppA) from H. influenzae
  • Lipoprotein xP55 from Streptomyces lividans
  • Hypothetical proteins from H. influenzae (HI0213) and Rhizobium sp. (strain NGR234) symbiotic plasmid (y4tO and y4wM)
  • HTH-type transcriptional regulator SgrR from E. coli. The solute-binding domain is localised in its C-terminal [PMID: 17209026].

Contributing signatures

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