Structure and catalytic activation of the TRIM23 RING E3 ubiquitin ligase

Proteins. 2017 Oct;85(10):1957-1961. doi: 10.1002/prot.25348. Epub 2017 Jul 24.


Tripartite motif (TRIM) proteins comprise a large family of RING-type ubiquitin E3 ligases that regulate important biological processes. An emerging general model is that TRIMs form elongated antiparallel coiled-coil dimers that prevent interaction of the two attendant RING domains. The RING domains themselves bind E2 conjugating enzymes as dimers, implying that an active TRIM ligase requires higher-order oligomerization of the basal coiled-coil dimers. Here, we report crystal structures of the TRIM23 RING domain in isolation and in complex with an E2-ubiquitin conjugate. Our results indicate that TRIM23 enzymatic activity requires RING dimerization, consistent with the general model of TRIM activation.

Keywords: E3 ligase; crystal structure; dimer; enzyme activation; tripartite motif; ubiquitination.

MeSH terms

  • Crystallography, X-Ray
  • Dimerization
  • GTP-Binding Proteins / chemistry*
  • GTP-Binding Proteins / metabolism
  • Humans
  • Protein Conformation*
  • Structure-Activity Relationship
  • Tripartite Motif Proteins / chemistry*
  • Tripartite Motif Proteins / metabolism
  • Ubiquitin-Protein Ligases / chemistry*
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitination


  • TRIM23 protein, human
  • Tripartite Motif Proteins
  • Ubiquitin-Protein Ligases
  • GTP-Binding Proteins

Associated data

  • PDB/5VZV
  • PDB/5VZW