This family represents a conserved region approximately 150 residues long within a number of eukaryotic proteins that show homology with Drosophila melanogaster Modifier of rudimentary (Mod(r)) proteins. The N-terminal half of Mod(r) proteins is acidic, whereas the C-terminal half is basic [1], and both of these regions are represented in this family. Members of this family include the Vps37 subunit of the endosomal sorting complex ESCRT-I, a complex involved in recruiting transport machinery for protein sorting at the multivesicular body (MVB). The yeast ESCRT-I complex consists of three proteins (Vps23, Vps28 and Vps37). The mammalian homologue of Vps37 interacts with Tsg101 (Pfam: PF05743) through its mod(r) domain and its function is essential for lysosomal sorting of EGF receptors [2].

1: Modifier of rudimentary p1, mod(r)p1, a trans-acting regulatory mutation of rudimentary. Begley D, Murphy AM, Hiu C, Tsubota SI; Mol Gen Genet 1995;248:69-78. PMID:7651329

2: The growth-regulatory protein HCRP1/hVps37A is a subunit of mammalian ESCRT-I and mediates receptor down-regulation. Bache KG, Slagsvold T, Cabezas A, Rosendal KR, Raiborg C, Stenmark H; Mol Biol Cell 2004;15:4337-4346. PMID:15240819