Intermediates in the Guanine Nucleotide Exchange Reaction of Rab8 Protein Catalyzed by Guanine Nucleotide Exchange Factors Rabin8 and GRAB.Guo, Z., Hou, X., Goody, R.S., Itzen, A.
(2013) J Biol Chem 288: 32466-32474
- PubMed: 24072714
- DOI: https://doi.org/10.1074/jbc.M113.498329
- Primary Citation of Related Structures:
4LHV, 4LHW, 4LHX, 4LHY, 4LHZ, 4LI0
- PubMed Abstract:
Small G-proteins of the Ras superfamily control the temporal and spatial coordination of intracellular signaling networks by acting as molecular on/off switches. Guanine nucleotide exchange factors (GEFs) regulate the activation of these G-proteins through catalytic replacement of GDP by GTP. During nucleotide exchange, three distinct substrate·enzyme complexes occur: a ternary complex with GDP at the start of the reaction (G-protein·GEF·GDP), an intermediary nucleotide-free binary complex (G-protein·GEF), and a ternary GTP complex after productive G-protein activation (G-protein·GEF·GTP). Here, we show structural snapshots of the full nucleotide exchange reaction sequence together with the G-protein substrates and products using Rabin8/GRAB (GEF) and Rab8 (G-protein) as a model system. Together with a thorough enzymatic characterization, our data provide a detailed view into the mechanism of Rabin8/GRAB-mediated nucleotide exchange.
From the Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany,; the Center for Integrated Protein Science Munich, Chemistry Department, Technische Universität München, 85747 Garching, Germany. Electronic address: email@example.com.