The retromer subunit Vps26 has an arrestin fold and binds Vps35 through its C-terminal domain.
Shi, H., Rojas, R., Bonifacino, J.S., Hurley, J.H.(2006) Nat Struct Mol Biol 13: 540-548
- PubMed: 16732284 
- DOI: https://doi.org/10.1038/nsmb1103
- Primary Citation of Related Structures:  
2FAU - PubMed Abstract: 
The mammalian retromer complex consists of SNX1, SNX2, Vps26, Vps29 and Vps35, and retrieves lysosomal enzyme receptors from endosomes to the trans-Golgi network. The structure of human Vps26A at 2.1-A resolution reveals two curved beta-sandwich domains connected by a polar core and a flexible linker. Vps26 has an unpredicted structural relationship to arrestins. The Vps35-binding site on Vps26 maps to a mobile loop spanning residues 235-246, near the tip of the C-terminal domain. The loop is phylogenetically conserved and provides a mechanism for Vps26 integration into the complex that leaves the rest of the structure free for engagements with membranes and for conformational changes. Hydrophobic residues and a glycine in this loop are required for integration into the retromer complex and endosomal localization of human Vps26, and for the function of yeast Vps26 in carboxypeptidase Y sorting.
Organizational Affiliation: 
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, US Department of Health and Human Services, Bethesda, Maryland 20892, USA.