EMD-17715

Single-particle
7.4 Å
EMD-17715 Deposition: 23/06/2023
Map released: 03/01/2024
Last modified: 31/01/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-17715

SRS and Cat modules of human CTLHSR4 bound to multiphosphorylated UBE2H~ubiquitin

EMD-17715

Single-particle
7.4 Å
EMD-17715 Deposition: 23/06/2023
Map released: 03/01/2024
Last modified: 31/01/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Homo sapiens
Sample: Complex of human CTLHSR4 E3 ligase bound to engineered ARMC8-specific VH and multiphosphorylated UBE2H~ubiquitin

Deposition Authors: Chrustowicz J, Sherpa D, Schulman BA
Multisite phosphorylation dictates selective E2-E3 pairing as revealed by Ubc8/UBE2H-GID/CTLH assemblies.
PUBMED: 38113892
DOI: doi:10.1016/j.molcel.2023.11.027
ISSN: 1097-2765
ASTM: MOCEFL
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.