2sns
From Proteopedia
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- | [[ | + | ==STAPHYLOCOCCAL NUCLEASE. PROPOSED MECHANISM OF ACTION BASED ON STRUCTURE OF ENZYME-THYMIDINE 3(PRIME),5(PRIME)-BIPHOSPHATE-CALCIUM ION COMPLEX AT 1.5-ANGSTROMS RESOLUTION== |
+ | <StructureSection load='2sns' size='340' side='right' caption='[[2sns]], [[Resolution|resolution]] 1.50Å' scene=''> | ||
+ | == Structural highlights == | ||
+ | <table><tr><td colspan='2'>[[2sns]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1sns 1sns]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2SNS OCA]. <br> | ||
+ | </td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=THP:THYMIDINE-3,5-DIPHOSPHATE'>THP</scene><br> | ||
+ | <tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucokinase Glucokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.2 2.7.1.2] </span></td></tr> | ||
+ | <tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2sns FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2sns OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2sns RCSB], [http://www.ebi.ac.uk/pdbsum/2sns PDBsum]</span></td></tr> | ||
+ | <table> | ||
+ | == Evolutionary Conservation == | ||
+ | [[Image:Consurf_key_small.gif|200px|right]] | ||
+ | Check<jmol> | ||
+ | <jmolCheckbox> | ||
+ | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/sn/2sns_consurf.spt"</scriptWhenChecked> | ||
+ | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
+ | <text>to colour the structure by Evolutionary Conservation</text> | ||
+ | </jmolCheckbox> | ||
+ | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | ||
+ | <div style="clear:both"></div> | ||
+ | <div style="background-color:#fffaf0;"> | ||
+ | == Publication Abstract from PubMed == | ||
+ | The structure of the staphylococcal nuclease (EC 3.1.4.7)-thymidine 3',5'-bisphosphate-Ca(2+) (enzyme-inhibitor) complex has been extended to 1.5-A resolution by using much additional data and a phase refinement scheme based on an electron-density map modification procedure. By correlating this structure with the known properties of the enzyme, a mechanism of action is proposed that involves nucleophilic attack on phosphorus by a water molecule, which is bound to Glu-43, in line with the 5'-CH(2)O(H) leaving group. The carboxylate of Glu-43 promotes this attack by acting as a general base for the abstraction of a proton from the attacking water molecule. Nucleophilic attack is further facilitated by polarization of the phosphodiester by an ionic interaction between a Ca(2+) ion and a phosphate oxygen atom and by four hydrogen bonds to phosphate oxygen atoms from guanidinium ions of Arg-35 and Arg-87. These interactions may also catalyze the reaction by lowering the energy of a trigonal bipyramidal transition state. The hydrolysis of nucleic acid substrate proceeds by cleavage of the 5'-P-O bond to yield a free 5'-hydroxyl group and a terminal, 3'-phosphate monoester group. In the inhibitor complex the only general acid group found in a position to donate a proton to the leaving 5'-oxygen is the guanidinium ion of Arg-87. Alternative proton donors, presently lacking direct structural support, could be the phenolic hydroxyl group of Tyr-113 or a water molecule. The precision and rigidity of the location of the reactants at the active site and the probable dual binding and catalytic roles of the guanidinium ions of Arg-35 and Arg-87 are especially noteworthy. | ||
- | + | Staphylococcal nuclease: proposed mechanism of action based on structure of enzyme-thymidine 3',5'-bisphosphate-calcium ion complex at 1.5-A resolution.,Cotton FA, Hazen EE Jr, Legg MJ Proc Natl Acad Sci U S A. 1979 Jun;76(6):2551-5. PMID:288045<ref>PMID:288045</ref> | |
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- | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
- | + | </div> | |
- | + | == References == | |
- | + | <references/> | |
- | + | __TOC__ | |
- | + | </StructureSection> | |
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- | == | + | |
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[[Category: Micrococcal nuclease]] | [[Category: Micrococcal nuclease]] | ||
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] |
Revision as of 08:39, 7 May 2014
STAPHYLOCOCCAL NUCLEASE. PROPOSED MECHANISM OF ACTION BASED ON STRUCTURE OF ENZYME-THYMIDINE 3(PRIME),5(PRIME)-BIPHOSPHATE-CALCIUM ION COMPLEX AT 1.5-ANGSTROMS RESOLUTION
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