Related Experiment Video
Updated: May 19, 2026
10:27
Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta
Published on: December 5, 2019
Structure of an E3:E2~Ub complex reveals an allosteric mechanism shared among RING/U-box ligases
Jonathan N Pruneda1, Peter J Littlefield, Sarah E Soss
1Department of Biochemistry, University of Washington, Seattle, WA 98195, USA.
Molecular Cell
|August 14, 2012
Summary
RING/U-box E3 ligases activate ubiquitin (Ub) transfer by biasing E2~Ub conformations. A key hydrogen bond allosterically activates E2~Ub, explaining RING/U-box ligase mechanisms.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- RING/U-box E3 ubiquitin ligases are crucial for ubiquitin signaling.
- The precise mechanism of ubiquitin transfer by these enzymes is not fully understood.
Purpose of the Study:
- To elucidate the mechanism of ubiquitin transfer by RING/U-box E3 ligases.
- To present a structural model of a RING/U-box E3:E2~Ub complex.
Main Methods:
- Structural modeling
- Biochemical analyses
Main Results:
- E3 binding induces closed conformations in E2~Ub, enhancing reactivity.
- A conserved hydrogen bond between E3 and E2 is identified as critical for allosteric activation.
- This mechanism is specific to RING/U-box E3s and not HECT-type E3s.
Conclusions:
- A structural model for RING/U-box E3:E2~Ub complex formation and activation is proposed.
- The study identifies the allosteric mechanism driving E2~Ub activation by RING/U-box ligases.
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