3MSH

Crystal structure of Hepatitis B X-Interacting Protein at high resolution

Summary for 3MSH

• Entry DOI: 10.2210/pdb3msh/pdb
• Related: 3MS6
• Descriptor: Hepatitis B virus X-interacting protein, GLYCEROL, ISOPROPYL ALCOHOL, ... (6 entities in total)
• Functional Keywords: alpha-beta proteins, profilin-like fold, roadblock/lc7 domain superfamily, protein binding
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm: O43504
• Total number of polymer chains: 1
• Total formula weight: 11255.63

Authors

Garcia-Saez, I.,Skoufias, D. (deposition date: 2010-04-29, release date: 2010-11-10, Last modification date: 2024-11-20)

Primary citation

Garcia-Saez, I.,Lacroix, F.B.,Blot, D.,Gabel, F.,Skoufias, D.A.
Structural Characterization of HBXIP: The Protein That Interacts with the Anti-Apoptotic Protein Survivin and the Oncogenic Viral Protein HBx.
J.Mol.Biol., 405:331-340, 2011

PubMed Abstract: Hepatitis B X-interacting protein (HBXIP) is a ubiquitous protein that was originally identified as a binding partner of the hepatitis B viral protein HBx. HBXIP is also thought to serve as an anti-apoptotic cofactor of survivin, promoting the suppression of pro-caspase-9 activation. Here were port the crystal structure of the shortest isoform of HBXIP (91 aa long,∼11 kDa) at 1.5 Å resolution. HBXIP crystal shows a monomer per asymmetric unit, with a profilin-like fold which is common to a super family of proteins, the Roadblock/LC7 domain family involved in protein-protein interactions. Based on this fold, we propose that HBXIP can form a dimer that can indeed be found in the crystal when symmetric molecules are generated around the asymmetric unit. This dimer shows an extended β-sheet area formed by 10 anti-parallel β-strands from both subunits. Another interesting aspect of the proposed HBXIP dimer interface is the presence of a small leucine zipper between the two α2 helices of each monomer. In solution, the scattering curve obtained by small-angle X-ray scattering for the sample used for crystallization indicates that the protein is dimeric form in solution. The fit between the experimental small angle X-ray scattering curve and the back calculated curves for two potential crystal dimers shows a significant preference for the Roadblock/LC7 fold dimer model. Moreover, the HBXIP crystal structure represents a step towards understanding the cellular role of HBXIP.

PubMed: 21059355
DOI: 10.1016/j.jmb.2010.10.046

Experimental method

X-RAY DIFFRACTION (1.51 Å)