ジャーナル: Nature / 年: 2021 タイトル: Structure of the class D GPCR Ste2 dimer coupled to two G proteins. 著者: Vaithish Velazhahan / Ning Ma / Gáspár Pándy-Szekeres / Albert J Kooistra / Yang Lee / David E Gloriam / Nagarajan Vaidehi / Christopher G Tate / 要旨: G-protein-coupled receptors (GPCRs) are divided phylogenetically into six classes, denoted A to F. More than 370 structures of vertebrate GPCRs (belonging to classes A, B, C and F) have been ...G-protein-coupled receptors (GPCRs) are divided phylogenetically into six classes, denoted A to F. More than 370 structures of vertebrate GPCRs (belonging to classes A, B, C and F) have been determined, leading to a substantial understanding of their function. By contrast, there are no structures of class D GPCRs, which are found exclusively in fungi where they regulate survival and reproduction. Here we determine the structure of a class D GPCR, the Saccharomyces cerevisiae pheromone receptor Ste2, in an active state coupled to the heterotrimeric G protein Gpa1-Ste4-Ste18. Ste2 was purified as a homodimer coupled to two G proteins. The dimer interface of Ste2 is formed by the N terminus, the transmembrane helices H1, H2 and H7, and the first extracellular loop ECL1. We establish a class D1 generic residue numbering system (CD1) to enable comparisons with orthologues and with other GPCR classes. The structure of Ste2 bears similarities in overall topology to class A GPCRs, but the transmembrane helix H4 is shifted by more than 20 Å and the G-protein-binding site is a shallow groove rather than a cleft. The structure provides a template for the design of novel drugs to target fungal GPCRs, which could be used to treat numerous intractable fungal diseases.
EMPIAR-10878 (タイトル: Structure of the ligand-free GPCR dimer Ste2 / Data size: 8.2 TB Data #1: unaligned multiframe micrographs of Ste2 in the ligand-free state [micrographs - multiframe])