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| {{STRUCTURE_1s8h| PDB=1s8h | SCENE= }} | | {{STRUCTURE_1s8h| PDB=1s8h | SCENE= }} |
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- | '''Crystal structure of Lys49-Phospholipase A2 from Agkistrodon contortrix laticinctus, first fatty acid free form'''
| + | ===Crystal structure of Lys49-Phospholipase A2 from Agkistrodon contortrix laticinctus, first fatty acid free form=== |
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- | ==Overview==
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- | Agkistrodon contortrix laticinctus myotoxin is a Lys(49)-phospholipase A(2) (EC 3.1.1.4) isolated from the venom of the serpent A. contortrix laticinctus (broad-banded copperhead). We present here three monomeric crystal structures of the myotoxin, obtained under different crystallization conditions. The three forms present notable structural differences and reveal that the presence of a ligand in the active site (naturally presumed to be a fatty acid) induces the exposure of a hydrophobic surface (the hydrophobic knuckle) toward the C terminus. The knuckle in A. contortrix laticinctus myotoxin involves the side chains of Phe(121) and Phe(124) and is a consequence of the formation of a canonical structure for the main chain within the region of residues 118-125. Comparison with other Lys(49)-phospholipase A(2) myotoxins shows that although the knuckle is a generic structural motif common to all members of the family, it is not readily recognizable by simple sequence analyses. An activation mechanism is proposed that relates fatty acid retention at the active site to conformational changes within the C-terminal region, a part of the molecule that has long been associated with Ca(2+)-independent membrane damaging activity and myotoxicity. This provides, for the first time, a direct structural connection between the phospholipase "active site" and the C-terminal "myotoxic site," justifying the otherwise enigmatic conservation of the residues of the former in supposedly catalytically inactive molecules.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_15596433}}, adds the Publication Abstract to the page |
| + | (as it appears on PubMed at http://www.pubmed.gov), where 15596433 is the PubMed ID number. |
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| + | {{ABSTRACT_PUBMED_15596433}} |
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| ==About this Structure== | | ==About this Structure== |
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| [[Category: Myotoxicity]] | | [[Category: Myotoxicity]] |
| [[Category: Snake venom]] | | [[Category: Snake venom]] |
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 08:25:38 2008'' | + | |
| + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 09:44:14 2008'' |
Revision as of 06:44, 28 July 2008
Template:STRUCTURE 1s8h
Crystal structure of Lys49-Phospholipase A2 from Agkistrodon contortrix laticinctus, first fatty acid free form
Template:ABSTRACT PUBMED 15596433
About this Structure
1S8H is a Single protein structure of sequence from Agkistrodon contortrix laticinctus. Full crystallographic information is available from OCA.
Reference
A molecular mechanism for Lys49-phospholipase A2 activity based on ligand-induced conformational change., Ambrosio AL, Nonato MC, de Araujo HS, Arni R, Ward RJ, Ownby CL, de Souza DH, Garratt RC, J Biol Chem. 2005 Feb 25;280(8):7326-35. Epub 2004 Dec 13. PMID:15596433
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