Structure of a RING E3 ligase and ubiquitin-loaded E2 primed for catalysis
| Autor: | Ronald T. Hay, Ellis Jaffray, Anna Plechanovová, James H. Naismith, Michael H. Tatham |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
0303 health sciences Isopeptide bond Multidisciplinary biology Stereochemistry Ubiquitin-Protein Ligases Active site Protomer Ubiquitin-conjugating enzyme Article 3. Good health Deubiquitinating enzyme Cell biology Ubiquitin ligase 03 medical and health sciences 0302 clinical medicine chemistry Ubiquitin biology.protein 030217 neurology & neurosurgery 030304 developmental biology |
| Zdroj: | Nature |
| ISSN: | 1476-4687 0028-0836 |
| Popis: | Ubiquitin modification is mediated by a large family of specificity determining ubiquitin E3 ligases. To facilitate ubiquitin transfer, RING E3 ligases bind both substrate and a ubiquitin E2 conjugating enzyme linked to ubiquitin via a thioester bond, but the mechanism of transfer has remained elusive. Here we report the crystal structure of the dimeric RING domain of rat RNF4 in complex with E2 (UbcH5A) linked by an isopeptide bond to ubiquitin. While the E2 contacts a single protomer of the RING, ubiquitin is folded back onto the E2 by contacts from both RING protomers. The carboxy-terminal tail of ubiquitin is locked into an active site groove on the E2 by an intricate network of interactions, resulting in changes at the E2 active site. This arrangement is primed for catalysis as it can deprotonate the incoming substrate lysine residue and stabilize the consequent tetrahedral transition-state intermediate. |
| Databáze: | OpenAIRE |
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