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== | ==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=''> | + | <StructureSection load='2sns' size='340' side='right'caption='[[2sns]], [[Resolution|resolution]] 1.50Å' scene=''> |
== Structural highlights == | == Structural highlights == | ||
| - | <table><tr><td colspan='2'>[[2sns]] is a 1 chain structure with sequence from [ | + | <table><tr><td colspan='2'>[[2sns]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2SNS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2SNS FirstGlance]. <br> |
| - | </td></tr><tr id=' | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.5Å</td></tr> |
| - | <tr id=' | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=THP:THYMIDINE-3,5-DIPHOSPHATE'>THP</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2sns FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2sns OCA], [https://pdbe.org/2sns PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2sns RCSB], [https://www.ebi.ac.uk/pdbsum/2sns PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2sns ProSAT]</span></td></tr> |
</table> | </table> | ||
== Function == | == Function == | ||
| - | [ | + | [https://www.uniprot.org/uniprot/NUC_STAAU NUC_STAAU] Enzyme that catalyzes the hydrolysis of both DNA and RNA at the 5' position of the phosphodiester bond. |
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
[[Image:Consurf_key_small.gif|200px|right]] | [[Image:Consurf_key_small.gif|200px|right]] | ||
Check<jmol> | Check<jmol> | ||
<jmolCheckbox> | <jmolCheckbox> | ||
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/sn/2sns_consurf.spt"</scriptWhenChecked> | + | <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/ | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> |
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
</jmolCheckbox> | </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/ | + | </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/main_output.php?pdb_ID=2sns ConSurf]. |
<div style="clear:both"></div> | <div style="clear:both"></div> | ||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
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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. | 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: | + | 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:000288045<ref>PMID:000288045</ref> |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | </div> | ||
| + | <div class="pdbe-citations 2sns" style="background-color:#fffaf0;"></div> | ||
| + | |||
| + | ==See Also== | ||
| + | *[[Staphylococcal nuclease 3D structures|Staphylococcal nuclease 3D structures]] | ||
== References == | == References == | ||
<references/> | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
| - | [[Category: | + | [[Category: Large Structures]] |
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
| - | [[Category: Cotton | + | [[Category: Cotton FA]] |
| - | [[Category: Hazen | + | [[Category: Hazen Jr EE]] |
| - | [[Category: Legg | + | [[Category: Legg MJ]] |
Current revision
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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