ABC transporter type 1, transmembrane domain MetI-like (IPR000515)

Short name: MetI-like

Overlapping homologous superfamilies

Domain relationships


ABC transporters are minimally constituted of two conserved regions: a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). These regions can be found on the same protein (mostly in eukaryotes and bacterial exporters) or on two different ones (mostly bacterial importers) [PMID: 9873074]. In importers, the TMD displays a distinctive signature, the EAA motif, a 20 amino acid conserved sequence located about 100 residues from the C terminus. The motif is hydrophilic and has been found to reside in a cytoplasmic loop located between the penultimate and the antepenultimate transmembrane segment in all proteins with a known topology [PMID: 7934906]. It appears to play an important role in ensuring the correct assembly of the prokaryotic ABC transport complex [PMID: 9640644] and constituting an interaction site with the so-called helical domain of the ABC module [PMID: 10809785, PMID: 9214624].

This entry recognises ABC transmembrane domains where the TMD is on a separate protein, such as the D-methionine transport system permease protein MetI. The crystal structure of the high-affinity Escherichia coli MetNI methionine uptake transporter has been solved. Each MetI subunit is organised around a core of five transmembrane helices that correspond to a subset of the helices observed in the larger membrane-spanning subunits of the molybdate (ModBC) and maltose (MalFGK) ABC transporters, which contain six helices [PMID: 18621668].

GO terms

Biological Process

GO:0055085 transmembrane transport

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0016020 membrane

Contributing signatures

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