1xxw
From Proteopedia
(New page: 200px<br /><applet load="1xxw" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xxw, resolution 2.70Å" /> '''Structure of zinc in...) |
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| - | [[Image:1xxw.gif|left|200px]]<br /><applet load="1xxw" size=" | + | [[Image:1xxw.gif|left|200px]]<br /><applet load="1xxw" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1xxw, resolution 2.70Å" /> | caption="1xxw, resolution 2.70Å" /> | ||
'''Structure of zinc induced heterodimer of two calcium free isoforms of phospholipase A2 from Naja naja sagittifera at 2.7A resolution'''<br /> | '''Structure of zinc induced heterodimer of two calcium free isoforms of phospholipase A2 from Naja naja sagittifera at 2.7A resolution'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of a zinc-induced heterodimer of two metal-free | + | The crystal structure of a zinc-induced heterodimer of two metal-free isoforms of a cobra venom phospholipase A(2) has been determined at 2.7 angstroms resolution. The crystals belong to space group P4(1), with unit-cell parameters a = b = 65.5, c = 58.4 angstroms, and have a single dimer in the asymmetric unit. The structure has been refined to R(cryst) and R(free) factors of 0.188 and 0.232, respectively. The two isoforms have a sequence identity of 82%. The zinc ion forms a fivefold coordination with a trigonal bipyramidal geometry involving one O atom each from Asp24 and Asn112 from molecule A and Asp24 from molecule B and two water molecules. Both molecules of the dimer are inactive. Molecule A is inactive because Arg31 (B) binds to Asp49 (A), while an acetate ion has displaced the essential water molecule and interacts with His48 (A). On the other hand, Arg31 (A) interacts with the calcium-binding loop of molecule B, resulting in an altered conformation of the loop. The absence of a calcium ion, loss of the essential water molecule and the altered conformation of the calcium-binding loop may be the reasons for the loss of activity of molecule B. |
==About this Structure== | ==About this Structure== | ||
| - | 1XXW is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Naja_sagittifera Naja sagittifera] with ZN and ACY as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] Full crystallographic information is available from [http:// | + | 1XXW is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Naja_sagittifera Naja sagittifera] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=ACY:'>ACY</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XXW OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Sharma, S.]] | [[Category: Sharma, S.]] | ||
[[Category: Singh, N.]] | [[Category: Singh, N.]] | ||
| - | [[Category: Singh, R | + | [[Category: Singh, R K.]] |
| - | [[Category: Singh, T | + | [[Category: Singh, T P.]] |
[[Category: Srinivasan, A.]] | [[Category: Srinivasan, A.]] | ||
| - | [[Category: Verma, A | + | [[Category: Verma, A K.]] |
[[Category: ACY]] | [[Category: ACY]] | ||
[[Category: ZN]] | [[Category: ZN]] | ||
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[[Category: zinc induced]] | [[Category: zinc induced]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:59:46 2008'' |
Revision as of 13:59, 21 February 2008
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Structure of zinc induced heterodimer of two calcium free isoforms of phospholipase A2 from Naja naja sagittifera at 2.7A resolution
Overview
The crystal structure of a zinc-induced heterodimer of two metal-free isoforms of a cobra venom phospholipase A(2) has been determined at 2.7 angstroms resolution. The crystals belong to space group P4(1), with unit-cell parameters a = b = 65.5, c = 58.4 angstroms, and have a single dimer in the asymmetric unit. The structure has been refined to R(cryst) and R(free) factors of 0.188 and 0.232, respectively. The two isoforms have a sequence identity of 82%. The zinc ion forms a fivefold coordination with a trigonal bipyramidal geometry involving one O atom each from Asp24 and Asn112 from molecule A and Asp24 from molecule B and two water molecules. Both molecules of the dimer are inactive. Molecule A is inactive because Arg31 (B) binds to Asp49 (A), while an acetate ion has displaced the essential water molecule and interacts with His48 (A). On the other hand, Arg31 (A) interacts with the calcium-binding loop of molecule B, resulting in an altered conformation of the loop. The absence of a calcium ion, loss of the essential water molecule and the altered conformation of the calcium-binding loop may be the reasons for the loss of activity of molecule B.
About this Structure
1XXW is a Protein complex structure of sequences from Naja sagittifera with and as ligands. Active as Phospholipase A(2), with EC number 3.1.1.4 Full crystallographic information is available from OCA.
Reference
Structure of the zinc-induced heterodimer of two calcium-free isoforms of phospholipase A2 from Naja naja sagittifera at 2.7 angstroms resolution., Jabeen T, Sharma S, Singh N, Singh RK, Verma AK, Paramasivam M, Srinivasan A, Singh TP, Acta Crystallogr D Biol Crystallogr. 2005 Mar;61(Pt 3):302-8. Epub 2005, Feb 24. PMID:15735340
Page seeded by OCA on Thu Feb 21 15:59:46 2008
Categories: Naja sagittifera | Phospholipase A(2) | Protein complex | Jabeen, T. | Paramasivam, M. | Sharma, S. | Singh, N. | Singh, R K. | Singh, T P. | Srinivasan, A. | Verma, A K. | ACY | ZN | Dimer | Esterolytic activity | Venom | Zinc induced
