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1ois

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Revision as of 10:03, 1 November 2017

YEAST DNA TOPOISOMERASE I, N-TERMINAL FRAGMENT

Structural highlights

1ois is a 1 chain structure with sequence from Atcc 18824. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Gene:	TOP1 (ATCC 18824)
Activity:	DNA topoisomerase, with EC number 5.99.1.2
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[TOP1_YEAST] 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 a target 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 (By similarity).

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

BACKGROUND: Type I DNA topoisomerases, divided mechanistically into two subfamilies, are ubiquitous enzymes that participate in replication and transcription. In addition to its role in these fundamental processes, the biological importance of eukaryotic DNA topoisomerase I is underscored by its identification as the target of the antitumor alkaloid camptothecin. An understanding of the mechanism of catalysis and interactions with camptothecin and other drugs has been hampered by a lack of detailed structural information. RESULTS: The three-dimensional structure of a 26 kDA fragment (residues 135 to about 363) of Saccharomyces cerevisiae DNA topoisomerase I has been determined at 1.9 A resolution. The fragment has a novel architecture comprising a concave platform and a pair of outlying V-shaped helices. Photocrosslinking and protein footprinting experiments show that the positively charged concave surface and the junction region of the V-shaped pair of helices contact DNA in the enzyme-DNA complex. CONCLUSIONS: Crystallographic, biochemical and genetic data indicate that this 26 kDa fragment of yeast DNA topoisomerase I is involved in complex formation between the enzyme and DNA, and probably also in camptothecin-enzyme-DNA ternary complex formation. A molecular model for protein-DNA interaction based on these data is proposed. The bipartite DNA-binding regions of the 26 kDa fragment may enable eukaryotic DNA topoisomerase I to adapt to sequence-dependent structural variations in its DNA substrates.

A 26 kDa yeast DNA topoisomerase I fragment: crystallographic structure and mechanistic implications.,Lue N, Sharma A, Mondragon A, Wang JC Structure. 1995 Dec 15;3(12):1315-22. PMID:8747458^[1]

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

References

↑ Lue N, Sharma A, Mondragon A, Wang JC. A 26 kDa yeast DNA topoisomerase I fragment: crystallographic structure and mechanistic implications. Structure. 1995 Dec 15;3(12):1315-22. PMID:8747458

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/1ois"

@@ Line 1: / Line 1: @@
 ==YEAST DNA TOPOISOMERASE I, N-TERMINAL FRAGMENT==
 <StructureSection load='1ois' size='340' side='right' caption='[[1ois]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
@@ Line 5: / Line 6: @@
 </td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">TOP1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4932 ATCC 18824])</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA_topoisomerase DNA topoisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.99.1.2 5.99.1.2] </span></td></tr>
-<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=1ois FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ois OCA], [http://pdbe.org/1ois PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ois RCSB], [http://www.ebi.ac.uk/pdbsum/1ois PDBsum]</span></td></tr>
+<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=1ois FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ois OCA], [http://pdbe.org/1ois PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ois RCSB], [http://www.ebi.ac.uk/pdbsum/1ois PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ois ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 17: / Line 18: @@
     <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].
+</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=1ois ConSurf].
 <div style="clear:both"></div>
 <div style="background-color:#fffaf0;">
@@ Line 28: / Line 29: @@
 </div>
 <div class="pdbe-citations 1ois" style="background-color:#fffaf0;"></div>
-==See Also==
-*[[Topoisomerase|Topoisomerase]]
 == References ==
 <references/>

1ois

From Proteopedia

Revision as of 10:03, 1 November 2017

YEAST DNA TOPOISOMERASE I, N-TERMINAL FRAGMENT

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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