Homologous Superfamily

VPS9 domain superfamily (IPR037191)

Short name: VPS9_dom_sf

Overlapping entries


Rab proteins form a family of signal-transducing GTPases that cycle between active GTP-bound and inactive GDP-bound forms. The Rab5 GTPase is an essential regulator of endocytosis and endosome biogenesis. Rab5 is activated by GDP-GTP exchange factors (GEFs) that contain a VPS9 domain and generate the Rab5-GTP complex [PMID: 16330212]. The VPS9 domain catalyzes nucleotide exchange on Rab5 or the yeast homologue VPS21. The domain has a length of ~140 residues and forms the central part of the yeast VPS9 (vacuolar protein sorting-associated) protein, which acts as a GEF for VPS21. Some domains which can occur in combination with the VPS9 domain are CUE, A20-type zinc finger, Ras-associating (RA), SH2, RCC1, DH, PH, rasGAP, MORN and ankyrin repeat.

Structurally, the VPS9 domain adopts a layered fold of six alpha helices. Conserved residues from the fourth and sixth helices and the loops N-terminal to these helices form the surface that interacts with Rab5 and Rab21 [PMID: 15339665].

Contributing signatures

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