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| | ==Crystal structure of Hepatitis B X-Interacting Protein (HBXIP)== | | ==Crystal structure of Hepatitis B X-Interacting Protein (HBXIP)== |
| - | <StructureSection load='3ms6' size='340' side='right' caption='[[3ms6]], [[Resolution|resolution]] 2.08Å' scene=''> | + | <StructureSection load='3ms6' size='340' side='right'caption='[[3ms6]], [[Resolution|resolution]] 2.08Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3ms6]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3MS6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3MS6 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3ms6]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3MS6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3MS6 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene></td></tr> |
| | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> | | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3msh|3msh]]</td></tr> | + | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[3msh|3msh]]</div></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HBXIP, XIP ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr> | + | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HBXIP, XIP ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr> |
| - | <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=3ms6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ms6 OCA], [http://pdbe.org/3ms6 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3ms6 RCSB], [http://www.ebi.ac.uk/pdbsum/3ms6 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3ms6 ProSAT]</span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3ms6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ms6 OCA], [https://pdbe.org/3ms6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ms6 RCSB], [https://www.ebi.ac.uk/pdbsum/3ms6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ms6 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/LTOR5_HUMAN LTOR5_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> | + | [[https://www.uniprot.org/uniprot/LTOR5_HUMAN LTOR5_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;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Human]] | | [[Category: Human]] |
| | + | [[Category: Large Structures]] |
| | [[Category: Garcia-Saez, I]] | | [[Category: Garcia-Saez, I]] |
| | [[Category: Skoufias, D]] | | [[Category: Skoufias, D]] |
| Structural highlights
Function
[LTOR5_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
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