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2sns

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Revision as of 23:10, 24 December 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

Structural highlights

2sns is a 1 chain structure with sequence from Staphylococcus aureus. This structure supersedes the now removed PDB entry 1sns. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Activity:	Micrococcal nuclease, with EC number 3.1.31.1
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[NUC_STAAU] Enzyme that catalyzes the hydrolysis of both DNA and RNA at the 5' position of the phosphodiester bond.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

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^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Cotton FA, Hazen EE Jr, Legg MJ. Staphylococcal nuclease: proposed mechanism of action based on structure of enzyme-thymidine 3',5'-bisphosphate-calcium ion complex at 1.5-A resolution. Proc Natl Acad Sci U S A. 1979 Jun;76(6):2551-5. PMID:288045

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2sns"

Categories: Micrococcal nuclease | Staphylococcus aureus | Cotton, F A | Hazen, E E | Legg, M J

@@ Line 7: / Line 7: @@
 <tr id='resources'><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>
+== Function ==
+[[http://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 ==
 [[Image:Consurf_key_small.gif|200px|right]]
@@ Line 31: / Line 33: @@
 [[Category: Micrococcal nuclease]]
 [[Category: Staphylococcus aureus]]
-[[Category: Cotton, F A.]]
+[[Category: Cotton, F A]]
-[[Category: Hazen, E E.]]
+[[Category: Hazen, E E]]
-[[Category: Legg, M J.]]
+[[Category: Legg, M J]]

2sns

From Proteopedia

Revision as of 23:10, 24 December 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

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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