5EIU: Mini TRIM5 B-box 2 dimer C2 crystal form

Restriction factors and pattern recognition receptors are important components of intrinsic cellular defenses against viral infection. Mammalian TRIM5alpha proteins are restriction factors and receptors that target the capsid cores of retroviruses and activate ubiquitin-dependent antiviral responses upon capsid recognition. Here, we report crystallographic and functional studies of the TRIM5alpha B-box 2 domain, which mediates higher-order assembly of TRIM5 proteins. The B-box can form both dimers and trimers, and the trimers can link multiple TRIM5alpha proteins into a hexagonal net that matches the lattice arrangement of capsid subunits and enables avid capsid binding. Two modes of conformational flexibility allow TRIM5alpha to accommodate the variable curvature of retroviral capsids. B-box mediated interactions also modulate TRIM5alpha's E3 ubiquitin ligase activity, by stereochemically restricting how the N-terminal RING domain can dimerize. Overall, these studies define important molecular details of cellular recognition of retroviruses, and how recognition links to downstream processes to disable the virus.
PDB ID: 5EIUDownload
MMDB ID: 140077
PDB Deposition Date: 2015/10/30
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 1.908  Å
Similar Structures:
Biological Unit for 5EIU: dimeric; determined by author
Molecular Components in 5EIU
Label Count Molecule
Proteins (2 molecules)
Trim Protein-e3 Ligase Chimera(Gene symbol: TRIM5)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB