1poa

<table><tr><td colspan='2'>[[1poa]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ansp_6988 Ansp 6988]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1POA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1POA FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] </span></td></tr>

[[https://www.uniprot.org/uniprot/PA2A1_NAJAT PA2A1_NAJAT]] Snake venom phospholipase A2 (PLA2) that has high affinity for muscarinic acetylcholine receptors mAChRs (CHRM) and has the ability to activate them. In guinea-pig ileum, produces an onset and dose-dependent contraction. Has also weak anticoagulant activity. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides.<ref>PMID:18281071</ref> <ref>PMID:3117784</ref>

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== Publication Abstract from PubMed ==

A chemical description of the action of phospholipase A2 (PLA2) can now be inferred with confidence from three high-resolution x-ray crystal structures. The first is the structure of the PLA2 from the venom of the Chinese cobra (Naja naja atra) in a complex with a phosphonate transition-state analogue. This enzyme is typical of a large, well-studied homologous family of PLA2S. The second is a similar complex with the evolutionarily distant bee-venom PLA2. The third structure is the uninhibited PLA2 from Chinese cobra venom. Despite the different molecular architectures of the cobra and bee-venom PLA2s, the transition-state analogue interacts in a nearly identical way with the catalytic machinery of both enzymes. The disposition of the fatty-acid side chains suggests a common access route of the substrate from its position in the lipid aggregate to its productive interaction with the active site. Comparison of the cobra-venom complex with the uninhibited enzyme indicates that optimal binding and catalysis at the lipid-water interface is due to facilitated substrate diffusion from the interfacial binding surface to the catalytic site rather than an allosteric change in the enzyme's structure. However, a second bound calcium ion changes its position upon the binding of the transition-state analogue, suggesting a mechanism for augmenting the critical electrophile.

Interfacial catalysis: the mechanism of phospholipase A2.,Scott DL, White SP, Otwinowski Z, Yuan W, Gelb MH, Sigler PB Science. 1990 Dec 14;250(4987):1541-6. PMID:2274785<ref>PMID:2274785</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1poa" style="background-color:#fffaf0;"></div>

[[Category: Ansp 6988]]

[[Category: Otwinowski, Z]]

[[Category: Scott, D L]]

[[Category: Sigler, P B]]

[[Category: Hydrolase]]