Structural basis for acidic-cluster-dileucine sorting-signal recognition by VHS domains.Misra, S., Puertollano, R., Kato, Y., Bonifacino, J.S., Hurley, J.H.
(2002) Nature 415: 933-937
- PubMed: 11859375
- DOI: https://doi.org/10.1038/415933a
- Primary Citation of Related Structures:
- PubMed Abstract:
Specific sorting signals direct transmembrane proteins to the compartments of the endosomal-lysosomal system. Acidic-cluster-dileucine signals present within the cytoplasmic tails of sorting receptors, such as the cation-independent and cation-dependent mannose-6-phosphate receptors, are recognized by the GGA (Golgi-localized, gamma-ear-containing, ADP-ribosylation-factor-binding) proteins. The VHS (Vps27p, Hrs and STAM) domains of the GGA proteins are responsible for the highly specific recognition of these acidic-cluster-dileucine signals. Here we report the structures of the VHS domain of human GGA3 complexed with signals from both mannose-6-phosphate receptors. The signals bind in an extended conformation to helices 6 and 8 of the VHS domain. The structures highlight an Asp residue separated by two residues from a dileucine sequence as critical recognition elements. The side chains of the Asp-X-X-Leu-Leu sequence interact with subsites consisting of one electropositive and two shallow hydrophobic pockets, respectively. The rigid spatial alignment of the three binding subsites leads to high specificity.
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.