7ns4
From Proteopedia
Catalytic module of yeast Chelator-GID SR4 E3 ubiquitin ligase
Structural highlights
FunctionRMD5_YEAST E3 ubiquitin-protein ligase component of the GID complex (PubMed:12686616, PubMed:18508925). Required for the adaptation to the presence of glucose in the growth medium; mediates the degradation of enzymes involved in gluconeogenesis when cells are shifted to glucose-containing medium (PubMed:18508925, PubMed:9737955). Required for proteasome-dependent catabolite degradation of fructose-1,6-bisphosphatase (FBP1) (PubMed:12686616, PubMed:18508925, PubMed:28126757, PubMed:9737955).[1] [2] [3] [4] Publication Abstract from PubMedHow are E3 ubiquitin ligases configured to match substrate quaternary structures? Here, by studying the yeast GID complex (mutation of which causes deficiency in glucose-induced degradation of gluconeogenic enzymes), we discover supramolecular chelate assembly as an E3 ligase strategy for targeting an oligomeric substrate. Cryoelectron microscopy (cryo-EM) structures show that, to bind the tetrameric substrate fructose-1,6-bisphosphatase (Fbp1), two minimally functional GID E3s assemble into the 20-protein Chelator-GID(SR4), which resembles an organometallic supramolecular chelate. The Chelator-GID(SR4) assembly avidly binds multiple Fbp1 degrons so that multiple Fbp1 protomers are simultaneously ubiquitylated at lysines near the allosteric and substrate binding sites. Importantly, key structural and biochemical features, including capacity for supramolecular assembly, are preserved in the human ortholog, the CTLH E3. Based on our integrative structural, biochemical, and cell biological data, we propose that higher-order E3 ligase assembly generally enables multipronged targeting, capable of simultaneously incapacitating multiple protomers and functionalities of oligomeric substrates. GID E3 ligase supramolecular chelate assembly configures multipronged ubiquitin targeting of an oligomeric metabolic enzyme.,Sherpa D, Chrustowicz J, Qiao S, Langlois CR, Hehl LA, Gottemukkala KV, Hansen FM, Karayel O, von Gronau S, Prabu JR, Mann M, Alpi AF, Schulman BA Mol Cell. 2021 Apr 22. pii: S1097-2765(21)00220-3. doi:, 10.1016/j.molcel.2021.03.025. PMID:33905682[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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