Download MendeleyInsights regarding guanine nucleotide exchange from the structure of a DENN-domain protein complexed with its Rab GTPase substrate.
Wu, X., Bradley, M.J., Cai, Y., Kummel, D., De La Cruz, E.M., Barr, F.A., Reinisch, K.M.(2011) Proc Natl Acad Sci U S A 108: 18672-18677
- PubMed: 22065758
- DOI: https://doi.org/10.1073/pnas.1110415108
- Primary Citation of Related Structures:
3TW8 - PubMed Abstract:
Rab GTPases are key regulators of membrane traffic pathways within eukaryotic cells. They are specifically activated by guanine nucleotide exchange factors (GEFs), which convert them from their "inactive" GDP-bound form to the "active" GTP-bound form. In higher eukaryotes, proteins containing DENN-domains comprise a major GEF family. Here we describe at 2.1-Å resolution the first structure of a DENN-domain protein, DENND1B-S, complexed with its substrate Rab35, providing novel insights as to how DENN-domain GEFs interact with and activate Rabs. DENND1B-S is bi-lobed, and interactions with Rab35 are through conserved surfaces in both lobes. Rab35 binds via switch regions I and II, around the nucleotide-binding pocket. Positional shifts in Rab residues required for nucleotide binding may lower its affinity for bound GDP, and a conformational change in switch I, which makes the nucleotide-binding pocket more solvent accessible, likely also facilitates exchange.
Organizational Affiliation:
Department of Cell Biology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
