1j34
From Proteopedia
(New page: 200px<br /><applet load="1j34" size="450" color="white" frame="true" align="right" spinBox="true" caption="1j34, resolution 1.55Å" /> '''Crystal Structure of...) |
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| - | [[Image:1j34.jpg|left|200px]]<br /><applet load="1j34" size=" | + | [[Image:1j34.jpg|left|200px]]<br /><applet load="1j34" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1j34, resolution 1.55Å" /> | caption="1j34, resolution 1.55Å" /> | ||
'''Crystal Structure of Mg(II)-and Ca(II)-bound Gla Domain of Factor IX Complexed with Binding Protein'''<br /> | '''Crystal Structure of Mg(II)-and Ca(II)-bound Gla Domain of Factor IX Complexed with Binding Protein'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Factor IX is an indispensable protein required in the blood coagulation | + | Factor IX is an indispensable protein required in the blood coagulation cascade. It binds to the surface of phospholipid membrane by means of a gamma-carboxyglutamic acid (Gla) domain situated at the N terminus. Recently, we showed that physiological concentrations of Mg2+ ions affect the native conformation of the Gla domain and in doing so augment the biological activity of factor IXa and binding affinity with its binding protein even in the presence of Ca2+ ions. Here we report on the crystal structures of the Mg2+/Ca2+-bound and Ca2+-bound (Mg2+-free) factor IX Gla domain (IXGD1-46) in complex with its binding protein (IX-bp) at 1.55 and 1.80 A resolutions, respectively. Three Mg2+ and five Ca2+ ions were bound in the Mg2+/Ca2+-bound IXGD1-46, and the Mg2+ ions were replaced by Ca2+ ions in Mg2+-free IXGD1-46. Comparison of Mg2+/Ca2+-bound with Ca2+-bound structures of the complexes showed that Mg2+ ion, which formed a bridge between IXGD1-46 and IX-bp, forced IXGD1-46 to rotate 4 degrees relative to IX-bp and hence might be the cause of a more tight interaction between the molecules than in the case of the Mg2+-free structure. The results clearly suggest that Mg2+ ions are required to maintain native conformation and in vivo function of factor IX Gla domain during blood coagulation. |
==About this Structure== | ==About this Structure== | ||
| - | 1J34 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] and [http://en.wikipedia.org/wiki/Trimeresurus_flavoviridis Trimeresurus flavoviridis] with MG and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Coagulation_factor_IXa Coagulation factor IXa], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.22 3.4.21.22] Full crystallographic information is available from [http:// | + | 1J34 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] and [http://en.wikipedia.org/wiki/Trimeresurus_flavoviridis Trimeresurus flavoviridis] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Coagulation_factor_IXa Coagulation factor IXa], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.22 3.4.21.22] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1J34 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: magnesium ion]] | [[Category: magnesium ion]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:18:27 2008'' |
Revision as of 11:18, 21 February 2008
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Crystal Structure of Mg(II)-and Ca(II)-bound Gla Domain of Factor IX Complexed with Binding Protein
Overview
Factor IX is an indispensable protein required in the blood coagulation cascade. It binds to the surface of phospholipid membrane by means of a gamma-carboxyglutamic acid (Gla) domain situated at the N terminus. Recently, we showed that physiological concentrations of Mg2+ ions affect the native conformation of the Gla domain and in doing so augment the biological activity of factor IXa and binding affinity with its binding protein even in the presence of Ca2+ ions. Here we report on the crystal structures of the Mg2+/Ca2+-bound and Ca2+-bound (Mg2+-free) factor IX Gla domain (IXGD1-46) in complex with its binding protein (IX-bp) at 1.55 and 1.80 A resolutions, respectively. Three Mg2+ and five Ca2+ ions were bound in the Mg2+/Ca2+-bound IXGD1-46, and the Mg2+ ions were replaced by Ca2+ ions in Mg2+-free IXGD1-46. Comparison of Mg2+/Ca2+-bound with Ca2+-bound structures of the complexes showed that Mg2+ ion, which formed a bridge between IXGD1-46 and IX-bp, forced IXGD1-46 to rotate 4 degrees relative to IX-bp and hence might be the cause of a more tight interaction between the molecules than in the case of the Mg2+-free structure. The results clearly suggest that Mg2+ ions are required to maintain native conformation and in vivo function of factor IX Gla domain during blood coagulation.
About this Structure
1J34 is a Protein complex structure of sequences from Bos taurus and Trimeresurus flavoviridis with and as ligands. Active as Coagulation factor IXa, with EC number 3.4.21.22 Full crystallographic information is available from OCA.
Reference
Crystal structure of Mg2+- and Ca2+-bound Gla domain of factor IX complexed with binding protein., Shikamoto Y, Morita T, Fujimoto Z, Mizuno H, J Biol Chem. 2003 Jun 27;278(26):24090-4. Epub 2003 Apr 14. PMID:12695512
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