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Structural Studies of HHARI/UbcH7∼Ub Reveal Unique E2∼Ub Conformational Restriction by RBR RING1
- Source :
- Structure (London, England : 1993). 25(6)
- Publication Year :
- 2016
-
Abstract
- RING-between-RING (RBR) E3s contain RING1 domains that are structurally similar yet mechanistically distinct from canonical RING domains. Both types of E3 bind E2∼ubiquitin (E2∼Ub) via their RINGs but canonical RING E3s promote closed E2∼Ub conformations required for direct Ub transfer from the E2 to substrate, while RBR RING1s promote open E2∼Ub to favor Ub transfer to the E3 active site. This different RING/E2∼Ub conformation determines its direct target, which for canonical RING E3s is typically a substrate or substrate-linked Ub, but is the E3 active-site cysteine in the case of RBR-type E3s. Here we show that a short extension of HHARI RING1, namely Zn2+-loop II, not present in any RING E3s, acts as a steric wedge to disrupt closed E2∼Ub, providing a structural explanation for the distinctive RING1-dependent conformational restriction mechanism utilized by RBR E3s.
- Subjects :
- 0301 basic medicine
Steric effects
Models, Molecular
Stereochemistry
Protein Conformation
Ubiquitin-Protein Ligases
Ubiquitin-conjugating enzyme
Ring (chemistry)
Crystallography, X-Ray
Canonical ring
03 medical and health sciences
Ubiquitin
Protein Domains
Structural Biology
Catalytic Domain
Transferase
Humans
Molecular Biology
Binding Sites
biology
Active site
3. Good health
Zinc
030104 developmental biology
Ubiquitin-Conjugating Enzymes
biology.protein
Carrier Proteins
Cysteine
Subjects
Details
- ISSN :
- 18784186
- Volume :
- 25
- Issue :
- 6
- Database :
- OpenAIRE
- Journal :
- Structure (London, England : 1993)
- Accession number :
- edsair.doi.dedup.....01fafa6dd510b756a35131f40cf91e06