3msh

From Proteopedia

(Difference between revisions)

Revision as of 21:18, 24 December 2014

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

Structural highlights

3msh is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, , ,
Related:	3ms6
Gene:	HBXIP, XIP (Homo sapiens)
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[HBXIP_HUMAN] As part of the Ragulator complex it is involved in amino acid sensing and activation of mTORC1, a signaling complex promoting cell growth in response to growth factors, energy levels, and amino acids. Activated by amino acids through a mechanism involving the lysosomal V-ATPase, the Ragulator functions as a guanine nucleotide exchange factor activating the small GTPases Rag. Activated Ragulator and Rag GTPases function as a scaffold recruiting mTORC1 to lysosomes where it is in turn activated. When complexed to BIRC5, interferes with apoptosome assembly, preventing recruitment of pro-caspase-9 to oligomerized APAF1, thereby selectively suppressing apoptosis initiated via the mitochondrial/cytochrome c pathway. Down-regulates hepatitis B virus (HBV) replication.^[1] ^[2]

Publication Abstract from PubMed

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, approximately 11 kDa) at 1.5 A 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 beta-sheet area formed by 10 anti-parallel beta-strands from both subunits. Another interesting aspect of the proposed HBXIP dimer interface is the presence of a small leucine zipper between the two alpha2 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.

Structural characterization of HBXIP: the protein that interacts with the anti-apoptotic protein survivin and the oncogenic viral protein HBx.,Garcia-Saez I, Lacroix FB, Blot D, Gabel F, Skoufias DA J Mol Biol. 2011 Jan 14;405(2):331-40. Epub 2010 Nov 6. PMID:21059355^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Marusawa H, Matsuzawa S, Welsh K, Zou H, Armstrong R, Tamm I, Reed JC. HBXIP functions as a cofactor of survivin in apoptosis suppression. EMBO J. 2003 Jun 2;22(11):2729-40. PMID:12773388 doi:10.1093/emboj/cdg263
↑ Bar-Peled L, Schweitzer LD, Zoncu R, Sabatini DM. Ragulator is a GEF for the rag GTPases that signal amino acid levels to mTORC1. Cell. 2012 Sep 14;150(6):1196-208. doi: 10.1016/j.cell.2012.07.032. PMID:22980980 doi:10.1016/j.cell.2012.07.032
↑ Garcia-Saez I, Lacroix FB, Blot D, Gabel F, Skoufias DA. Structural Characterization of HBXIP: The Protein That Interacts with the Anti-Apoptotic Protein Survivin and the Oncogenic Viral Protein HBx. J Mol Biol. 2010 Nov 6. PMID:21059355 doi:10.1016/j.jmb.2010.10.046

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3msh"

@@ Line 8: / Line 8: @@
 <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3msh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3msh OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3msh RCSB], [http://www.ebi.ac.uk/pdbsum/3msh PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/HBXIP_HUMAN HBXIP_HUMAN]] As part of the Ragulator complex it is involved in amino acid sensing and activation of mTORC1, a signaling complex promoting cell growth in response to growth factors, energy levels, and amino acids. Activated by amino acids through a mechanism involving the lysosomal V-ATPase, the Ragulator functions as a guanine nucleotide exchange factor activating the small GTPases Rag. Activated Ragulator and Rag GTPases function as a scaffold recruiting mTORC1 to lysosomes where it is in turn activated. When complexed to BIRC5, interferes with apoptosome assembly, preventing recruitment of pro-caspase-9 to oligomerized APAF1, thereby selectively suppressing apoptosis initiated via the mitochondrial/cytochrome c pathway. Down-regulates hepatitis B virus (HBV) replication.<ref>PMID:12773388</ref> <ref>PMID:22980980</ref>
 <div style="background-color:#fffaf0;">
 == Publication Abstract from PubMed ==

3msh

From Proteopedia

Revision as of 21:18, 24 December 2014

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

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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