This domain is found on the vacuolar sorting protein Vps39 which is a component of the C-Vps complex [2]. Vps39 is thought to be required for the fusion of endosomes and other types of transport intermediates with the vacuole [3]. In Saccharomyces cerevisiae, Vps39 has been shown to stimulate nucleotide exchange [1]. The precise function of this domain has not been characterised.

1: New component of the vacuolar class C-Vps complex couples nucleotide exchange on the Ypt7 GTPase to SNARE-dependent docking and fusion. Wurmser AE, Sato TK, Emr SD; J Cell Biol. 2000;151:551-562. PMID:11062257

2: Vam2/Vps41p and Vam6/Vps39p are components of a protein complex on the vacuolar membranes and involved in the vacuolar assembly in the yeast Saccharomyces cerevisiae. Nakamura N, Hirata A, Ohsumi Y, Wada Y; J Biol Chem. 1997;272:11344-11349. PMID:9111041

3: Morphological classification of the yeast vacuolar protein sorting mutants: evidence for a prevacuolar compartment in class E vps mutants. Raymond CK, Howald-Stevenson I, Vater CA, Stevens TH; Mol Biol Cell. 1992;3:1389-1402. PMID:1493335