1a2a: Difference between revisions
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[[Image:1a2a.gif|left|200px]]<br /><applet load="1a2a" size=" | [[Image:1a2a.gif|left|200px]]<br /><applet load="1a2a" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1a2a, resolution 2.80Å" /> | caption="1a2a, resolution 2.80Å" /> | ||
'''AGKISTROTOXIN, A PHOSPHOLIPASE A2-TYPE PRESYNAPTIC NEUROTOXIN FROM AGKISTRODON HALYS PALLAS'''<br /> | '''AGKISTROTOXIN, A PHOSPHOLIPASE A2-TYPE PRESYNAPTIC NEUROTOXIN FROM AGKISTRODON HALYS PALLAS'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
1A2A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gloydius_halys Gloydius halys] with CL as [http://en.wikipedia.org/wiki/ligand ligand]. 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] Known structural/functional Site: <scene name='pdbsite=NIC:Turn 55-61 And Stretch 85-91 Form A Possible Neurotoxic ...'>NIC</scene>. Full crystallographic information is available from [http:// | 1A2A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gloydius_halys Gloydius halys] with <scene name='pdbligand=CL:'>CL</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. 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] Known structural/functional Site: <scene name='pdbsite=NIC:Turn+55-61+And+Stretch+85-91+Form+A+Possible+Neurotoxic+...'>NIC</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1A2A OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: presynaptic neurotoxin]] | [[Category: presynaptic neurotoxin]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:28:40 2008'' | ||
Revision as of 10:28, 3 February 2008
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AGKISTROTOXIN, A PHOSPHOLIPASE A2-TYPE PRESYNAPTIC NEUROTOXIN FROM AGKISTRODON HALYS PALLAS
OverviewOverview
The crystal structure of agkistrodotoxin containing eight copies of, molecules in the asymmetric unit has been determined at 2.8 A resolution, to a crystallographic R factor of 0.207 by the molecular replacement, technique. Two spatially adjacent regions of agkistrodotoxin molecule, turn 55-61 and stretch 85-91, are remarkably different from those of, non-neurotoxic isoforms in conformation and electrostatic characteristics., These regions are likely to be involved in the recognition of, agkistrodotoxin towards the specific receptor at the presynaptic membrane., The structural comparison of the interfacial recognition site with, non-neurotoxic isoforms reveals a decreased hydrophobicity and lack of, residues with bulky hydrophobic side-chains (i.e. Trp) to serve as, membrane anchors. This structural feature of agkistrodotoxin may be, related to the reduced non-specific binding of the toxin to non-targeted, membrane before it arrives at the presynaptic membrane and recognizes the, putative receptor. A unique hydrophobic patch including residues I19, P20, F21, A23, F24, M118 and F119 is found on the surface of the molecule near, the entrance of the hydrophobic channel which plays an important role in, crystal packing. The interaction mode between the patches might give a, clue to the binding of the neurotoxin on the membrane. The agkistrodotoxin, molecules in the asymmetric unit form two tetramers and each tetramer, exhibits a novel "dimer of dimers"-like structure. A molecule-spanning, four-stranded antiparallel beta-sheet is formed by the beta-wings of two, molecules within a tetramer.
About this StructureAbout this Structure
1A2A is a Single protein structure of sequence from Gloydius halys with as ligand. Active as Phospholipase A(2), with EC number 3.1.1.4 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of agkistrodotoxin, a phospholipase A2-type presynaptic neurotoxin from agkistrodon halys pallas., Tang L, Zhou YC, Lin ZJ, J Mol Biol. 1998 Sep 11;282(1):1-11. PMID:9733637
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