1x2t
From Proteopedia
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|PDB= 1x2t |SIZE=350|CAPTION= <scene name='initialview01'>1x2t</scene>, resolution 1.72Å | |PDB= 1x2t |SIZE=350|CAPTION= <scene name='initialview01'>1x2t</scene>, resolution 1.72Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=1PE:PENTAETHYLENE+GLYCOL'>1PE</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1x2w|1X2W]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1x2t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1x2t OCA], [http://www.ebi.ac.uk/pdbsum/1x2t PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1x2t RCSB]</span> | ||
}} | }} | ||
| Line 27: | Line 30: | ||
[[Category: Morita, T.]] | [[Category: Morita, T.]] | ||
[[Category: Suzuki, N.]] | [[Category: Suzuki, N.]] | ||
| - | [[Category: 1PE]] | ||
| - | [[Category: CA]] | ||
[[Category: c-type lectin-like protein]] | [[Category: c-type lectin-like protein]] | ||
[[Category: domain swapping]] | [[Category: domain swapping]] | ||
[[Category: heterodimer]] | [[Category: heterodimer]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:44:09 2008'' |
Revision as of 21:44, 30 March 2008
| |||||||
| , resolution 1.72Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Related: | 1X2W
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of Habu IX-bp at pH 6.5
Overview
Coagulation factor IX-binding protein, isolated from Trimeresurus flavoviridis (IX-bp), is a C-type lectin-like protein. It is an anticoagulant consisting of homologous subunits, A and B. Each subunit has a Ca(2+)-binding site with a unique affinity (K(d) values of 14muM and 130muM at pH 7.5). These binding characteristics are pH-dependent and, under acidic conditions, the Ca(2+) binding of the low-affinity site was reduced considerably. In order to identify which site has high affinity and to investigate the pH-dependent Ca(2+) release mechanism, we have determined the crystal structures of IX-bp at pH 6.5 and pH 4.6 (apo form), and compared the Ca(2+)-binding sites with each other and with those of the solved structures under alkaline conditions; pH 7.8 and pH 8.0 (complexed form). At pH 6.5, Glu43 in the Ca(2+)-binding site of subunit A displayed two conformations. One (minor) is that in the alkaline state, and the other (major) is that at pH 4.6. However, the corresponding Gln43 residue of subunit B is in only a single conformation, which is almost identical with that in the alkaline state. At pH 4.6, Glu43 of subunit A adopts a conformation similar to that of the major conformer observed at pH 6.5, while Gln43 of subunit B assumes a new conformation, and both Ca(2+) positions are occupied by water molecules. These results showed that Glu43 of subunit A is much more sensitive to protonation than Gln43 of subunit B, and the conformational change of Glu43 occurs around pH6.5, which may correspond to the step of Ca(2+) release.
About this Structure
1X2T is a Protein complex structure of sequences from Trimeresurus flavoviridis. Full crystallographic information is available from OCA.
Reference
pH-Dependent structural changes at Ca(2+)-binding sites of coagulation factor IX-binding protein., Suzuki N, Fujimoto Z, Morita T, Fukamizu A, Mizuno H, J Mol Biol. 2005 Oct 14;353(1):80-7. PMID:16165155
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