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1a41

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Revision as of 07:00, 25 December 2014

TYPE 1-TOPOISOMERASE CATALYTIC FRAGMENT FROM VACCINIA VIRUS

Structural highlights

1a41 is a 1 chain structure with sequence from Vaccinia virus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Activity:	DNA topoisomerase, with EC number 5.99.1.2
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[TOP1_VACCW] Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at the specific target site 5'-[CT]CCTTp site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone.^[1] ^[2]

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

Vaccinia DNA topoisomerase breaks and rejoins DNA strands through a DNA-(3'-phosphotyrosyl)-enzyme intermediate. A C-terminal catalytic domain, Topo(81-314), suffices for transesterification chemistry. The domain contains a constellation of five amino acids, conserved in all eukaryotic type IB topoisomerases, that catalyzes attack of the tyrosine nucleophile on the scissile phosphate. The structure of the catalytic domain, consisting of ten alpha helices and a three-strand beta sheet, resembles the catalytic domains of site-specific recombinases that act via a topoisomerase IB-like mechanism. The topoisomerase catalytic pentad is conserved in the tertiary structures of the recombinases despite scant sequence similarity overall. This implies that the catalytic domains of type IB topoisomerases and recombinases derive from a common ancestral strand transferase.

Conservation of structure and mechanism between eukaryotic topoisomerase I and site-specific recombinases.,Cheng C, Kussie P, Pavletich N, Shuman S Cell. 1998 Mar 20;92(6):841-50. PMID:9529259^[3]

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

References

↑ Nagarajan R, Stivers JT. Major groove interactions of vaccinia Topo I provide specificity by optimally positioning the covalent phosphotyrosine linkage. Biochemistry. 2006 May 9;45(18):5775-82. PMID:16669621 doi:http://dx.doi.org/10.1021/bi060133i
↑ Stahley MR, Stivers JT. Mechanism and specificity of DNA strand exchange catalyzed by vaccinia DNA topoisomerase type I. Biochemistry. 2010 Apr 6;49(13):2786-95. PMID:20187656 doi:10.1021/bi902204v
↑ Cheng C, Kussie P, Pavletich N, Shuman S. Conservation of structure and mechanism between eukaryotic topoisomerase I and site-specific recombinases. Cell. 1998 Mar 20;92(6):841-50. PMID:9529259

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1a41"

@@ 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=1a41 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1a41 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1a41 RCSB], [http://www.ebi.ac.uk/pdbsum/1a41 PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/TOP1_VACCW TOP1_VACCW]] Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at the specific target site 5'-[CT]CCTTp site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone.<ref>PMID:16669621</ref> <ref>PMID:20187656</ref>
 == Evolutionary Conservation ==
 [[Image:Consurf_key_small.gif|200px|right]]

1a41

From Proteopedia

Revision as of 07:00, 25 December 2014

TYPE 1-TOPOISOMERASE CATALYTIC FRAGMENT FROM VACCINIA VIRUS

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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