Structure of an insect gustatory receptor.

Autor:	Frank HM; Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA.; These authors contributed equally., Walujkar S; Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA.; These authors contributed equally., Walsh RM Jr; The Harvard Cryo-EM Center for Structural Biology, Harvard Medical School, Boston, MA 02115, USA.; Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.; These authors contributed equally., Laursen WJ; Department of Biology and Volen Center for Complex Systems, Brandeis University, Waltham, MA 02453, USA., Theobald DL; Department of Biochemistry, Brandeis University, Waltham, MA 02453, USA., Garrity PA; Department of Biology and Volen Center for Complex Systems, Brandeis University, Waltham, MA 02453, USA., Gaudet R; Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA.; Lead contact.
Jazyk:	angličtina
Zdroj:	BioRxiv : the preprint server for biology [bioRxiv] 2023 Dec 19. Date of Electronic Publication: 2023 Dec 19.
DOI:	10.1101/2023.12.19.572336
Abstrakt:	Gustatory Receptors (GRs) are critical for insect chemosensation and are potential targets for controlling pests and disease vectors. However, GR structures have not been experimentally determined. We present structures of Bombyx mori Gr9 (BmGr9), a fructose-gated cation channel, in agonist-free and fructose-bound states. BmGr9 forms a tetramer similar to distantly related insect Olfactory Receptors (ORs). Upon fructose binding, BmGr9's ion channel gate opens through helix S7b movements. In contrast to ORs, BmGR9's ligand-binding pocket, shaped by a kinked helix S4 and a shorter extracellular S3-S4 loop, is larger and solvent accessible in both agonist-free and fructose-bound states. Also unlike ORs, fructose binding by BmGr9 involves helix S5 and a binding pocket lined with aromatic and polar residues. Structure-based sequence alignments reveal distinct patterns of ligand-binding pocket residue conservation in GR subfamilies associated with distinct ligand classes. These data provide insight into the molecular basis of GR ligand specificity and function. Competing Interests: Declaration of interests The authors declare no competing interests.
Databáze:	MEDLINE
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