Homologous Superfamily

Type II secretion system protein M, periplasmic domain superfamily (IPR023229)

Short name: T2SS_M_periplasmic_sf


Type II secretion system protein M is a membrane protein involved in the export of proteins in bacteria. It consists of a short cytosolic N-terminal domain, a transmembrane domain, and a C-terminal periplasmic domain. The precise function of this protein is unknown, though in Vibrio cholerae, the EpsM protein interacts with the EpsL protein, and also forms homodimers [PMID: 10322014].

The periplasmic domain forms a sandwich consisting of two alpha-helices and a four-stranded antiparallel beta-sheet [PMID: 15081815]. The overall fold is a circular permutation of the ferredoxin fold. In the dimer, a deep cleft with a polar rim and a hydrophobic bottom made by conserved residues is located between the monomers. This cleft contains an extra electron density suggesting that this region might serve as a binding site of an unknown ligand or part of a protein partner.

Contributing signatures

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