2LGV

Rbx1

Summary for 2LGV

• Entry DOI: 10.2210/pdb2lgv/pdb
• Related: 1LDJ 1LDK 1U6G 2HYE 3DPL 3DQV 3RTR
• NMR Information: BMRB: 17824
• Descriptor: E3 ubiquitin-protein ligase RBX1, ZINC ION (2 entities in total)
• Functional Keywords: roc1, ring, zn-binding, ligase
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm: P62877
• Total number of polymer chains: 1
• Total formula weight: 11371.78

Authors

Spratt, D.E.,Shaw, G.S. (deposition date: 2011-08-02, release date: 2012-03-28, Last modification date: 2024-05-15)

Primary citation

Spratt, D.E.,Wu, K.,Kovacev, J.,Pan, Z.Q.,Shaw, G.S.
Selective recruitment of an e2~ubiquitin complex by an e3 ubiquitin ligase.
J.Biol.Chem., 287:17374-17385, 2012

PubMed Abstract: RING E3 ligases are proteins that must selectively recruit an E2-conjugating enzyme and facilitate ubiquitin transfer to a substrate. It is not clear how a RING E3 ligase differentiates a naked E2 enzyme from the E2∼ubiquitin-conjugated form or how this is altered upon ubiquitin transfer. RING-box protein 1 (Rbx1/ROC1) is a key protein found in the Skp1/Cullin-1/F-box (SCF) E3 ubiquitin ligase complex that functions with the E2 ubiquitin conjugating enzyme CDC34. The solution structure of Rbx1/ROC1 revealed a globular RING domain (residues 40-108) stabilized by three structural zinc ions (root mean square deviation 0.30 ± 0.04 Å) along with a disordered N terminus (residues 12-39). Titration data showed that Rbx1/ROC1 preferentially recruits CDC34 in its ubiquitin-conjugated form and favors this interaction by 50-fold compared with unconjugated CDC34. Furthermore, NMR and biochemical assays identified residues in helix α2 of Rbx1/ROC1 that are essential for binding and activating CDC34∼ubiquitin for ubiquitylation. Taken together, this work provides the first direct structural and biochemical evidence showing that polyubiquitylation by the RING E3 ligase Rbx1/ROC1 requires the preferential recruitment of an E2∼ubiquitin complex and subsequent release of the unconjugated E2 protein upon ubiquitin transfer to a substrate or ubiquitin chain.

PubMed: 22433864
DOI: 10.1074/jbc.M112.353748

Experimental method

SOLUTION NMR