EMD-17713
Catalytic module of human CTLH E3 ligase bound to multiphosphorylated UBE2H~ubiquitin
EMD-17713
Single-particle3.4 Å
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Map released: 03/01/2024
Last modified: 13/11/2024
Sample Organism:
Homo sapiens
Sample: Complex of human CTLHSR4 E3 ligase bound to engineered ARMC8-specific VH and multiphosphorylated UBE2H~ubiquitin
Fitted models: 8pjn (Avg. Q-score: 0.529)
Deposition Authors: Chrustowicz J, Sherpa D, Prabu RJ, Schulman BA
Sample: Complex of human CTLHSR4 E3 ligase bound to engineered ARMC8-specific VH and multiphosphorylated UBE2H~ubiquitin
Fitted models: 8pjn (Avg. Q-score: 0.529)
Deposition Authors: Chrustowicz J, Sherpa D, Prabu RJ, Schulman BA
Multisite phosphorylation dictates selective E2-E3 pairing as revealed by Ubc8/UBE2H-GID/CTLH assemblies.
Chrustowicz J,
Sherpa D,
Li J
,
Langlois CR,
Papadopoulou EC,
Vu DT,
Hehl LA,
Karayel O,
Beier V,
von Gronau S,
Muller J,
Prabu JR,
Mann M,
Kleiger G,
Alpi AF
,
Schulman BA
(2024) Mol Cell , 84 , 293
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(2024) Mol Cell , 84 , 293
Abstract:
Ubiquitylation is catalyzed by coordinated actions of E3 and E2 enzymes. Molecular principles governing many important E3-E2 partnerships remain unknown, including those for RING-family GID/CTLH E3 ubiquitin ligases and their dedicated E2, Ubc8/UBE2H (yeast/human nomenclature). GID/CTLH-Ubc8/UBE2H-mediated ubiquitylation regulates biological processes ranging from yeast metabolic signaling to human development. Here, cryoelectron microscopy (cryo-EM), biochemistry, and cell biology reveal this exquisitely specific E3-E2 pairing through an unconventional catalytic assembly and auxiliary interactions 70-100 Å away, mediated by E2 multisite phosphorylation. Rather than dynamic polyelectrostatic interactions reported for other ubiquitylation complexes, multiple Ubc8/UBE2H phosphorylation sites within acidic CK2-targeted sequences specifically anchor the E2 C termini to E3 basic patches. Positions of phospho-dependent interactions relative to the catalytic domains correlate across evolution. Overall, our data show that phosphorylation-dependent multivalency establishes a specific E3-E2 partnership, is antagonistic with dephosphorylation, rigidifies the catalytic centers within a flexing GID E3-substrate assembly, and facilitates substrate collision with ubiquitylation active sites.
Ubiquitylation is catalyzed by coordinated actions of E3 and E2 enzymes. Molecular principles governing many important E3-E2 partnerships remain unknown, including those for RING-family GID/CTLH E3 ubiquitin ligases and their dedicated E2, Ubc8/UBE2H (yeast/human nomenclature). GID/CTLH-Ubc8/UBE2H-mediated ubiquitylation regulates biological processes ranging from yeast metabolic signaling to human development. Here, cryoelectron microscopy (cryo-EM), biochemistry, and cell biology reveal this exquisitely specific E3-E2 pairing through an unconventional catalytic assembly and auxiliary interactions 70-100 Å away, mediated by E2 multisite phosphorylation. Rather than dynamic polyelectrostatic interactions reported for other ubiquitylation complexes, multiple Ubc8/UBE2H phosphorylation sites within acidic CK2-targeted sequences specifically anchor the E2 C termini to E3 basic patches. Positions of phospho-dependent interactions relative to the catalytic domains correlate across evolution. Overall, our data show that phosphorylation-dependent multivalency establishes a specific E3-E2 partnership, is antagonistic with dephosphorylation, rigidifies the catalytic centers within a flexing GID E3-substrate assembly, and facilitates substrate collision with ubiquitylation active sites.