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1r49

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Revision as of 07:19, 6 January 2015

Human topoisomerase I (Topo70) double mutant K532R/Y723F

Structural highlights

1r49 is a 3 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	1a36, 1ej9, 1k4s, 1k4t, 1lpq, 1tmc
Gene:	TOP1 (Homo sapiens)
Activity:	DNA topoisomerase, with EC number 5.99.1.2
Resources:	FirstGlance, OCA, RCSB, PDBsum

Disease

[TOP1_HUMAN] Note=A chromosomal aberration involving TOP1 is found in a form of therapy-related myelodysplastic syndrome. Translocation t(11;20)(p15;q11) with NUP98.

Function

[TOP1_HUMAN] 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). Regulates the alternative splicing of tissue factor (F3) pre-mRNA in endothelial cells.^[1] ^[2] ^[3] ^[4]

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

Based on co-crystal structures of human topoisomerase I with bound DNA, Lys(532) makes a minor groove contact with the strongly preferred thymidine residue at the site of covalent attachment (-1 position). Replacement of Lys(532) with either arginine or alanine has essentially no effect on the sequence preference of the enzyme, indicating that this interaction is not required for the preference for a T at the -1 position. Although both the cleavage and religation activities of the K532R mutant enzyme are reduced, cleavage is reduced to a greater extent than religation. The reverse is true for the K532A mutant enzyme with religation so impaired that the nicked intermediate accumulates during plasmid relaxation assays. Consistent with the shift in the cleavage religation equilibrium toward cleavage for the K532A mutant enzyme, expression of the mutant enzyme in Saccharomyces cerevisiae is cytotoxic, and thus this mutant enzyme mimics the effects of the anticancer drug camptothecin. Cleavage assays with the mutant enzymes using an oligonucleotide containing a 5'-bridging phosphorothiolate indicate that Lys(532) functions as a general acid during cleavage to protonate the leaving 5'-oxygen. It is possible that the contact with the -1 base is important during catalysis to provide positional rigidity to the active site. The corresponding residues in the vaccinia virus topoisomerase and the tyrosine recombinases may have similar critical roles in catalysis.

The role of lysine 532 in the catalytic mechanism of human topoisomerase I.,Interthal H, Quigley PM, Hol WG, Champoux JJ J Biol Chem. 2004 Jan 23;279(4):2984-92. Epub 2003 Oct 31. PMID:14594810^[5]

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

References

↑ D'Arpa P, Machlin PS, Ratrie H 3rd, Rothfield NF, Cleveland DW, Earnshaw WC. cDNA cloning of human DNA topoisomerase I: catalytic activity of a 67.7-kDa carboxyl-terminal fragment. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2543-7. PMID:2833744
↑ Eisenreich A, Bogdanov VY, Zakrzewicz A, Pries A, Antoniak S, Poller W, Schultheiss HP, Rauch U. Cdc2-like kinases and DNA topoisomerase I regulate alternative splicing of tissue factor in human endothelial cells. Circ Res. 2009 Mar 13;104(5):589-99. doi: 10.1161/CIRCRESAHA.108.183905. Epub, 2009 Jan 22. PMID:19168442 doi:10.1161/CIRCRESAHA.108.183905
↑ Interthal H, Quigley PM, Hol WG, Champoux JJ. The role of lysine 532 in the catalytic mechanism of human topoisomerase I. J Biol Chem. 2004 Jan 23;279(4):2984-92. Epub 2003 Oct 31. PMID:14594810 doi:10.1074/jbc.M309959200
↑ Ioanoviciu A, Antony S, Pommier Y, Staker BL, Stewart L, Cushman M. Synthesis and mechanism of action studies of a series of norindenoisoquinoline topoisomerase I poisons reveal an inhibitor with a flipped orientation in the ternary DNA-enzyme-inhibitor complex as determined by X-ray crystallographic analysis. J Med Chem. 2005 Jul 28;48(15):4803-14. PMID:16033260 doi:10.1021/jm050076b
↑ Interthal H, Quigley PM, Hol WG, Champoux JJ. The role of lysine 532 in the catalytic mechanism of human topoisomerase I. J Biol Chem. 2004 Jan 23;279(4):2984-92. Epub 2003 Oct 31. PMID:14594810 doi:10.1074/jbc.M309959200

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1r49"

@@ Line 3: / Line 3: @@
 == Structural highlights ==
 <table><tr><td colspan='2'>[[1r49]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R49 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1R49 FirstGlance]. <br>
-</td></tr><tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1a36|1a36]], [[1ej9|1ej9]], [[1k4s|1k4s]], [[1k4t|1k4t]], [[1lpq|1lpq]], [[1tmc|1tmc]]</td></tr>
+</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1a36|1a36]], [[1ej9|1ej9]], [[1k4s|1k4s]], [[1k4t|1k4t]], [[1lpq|1lpq]], [[1tmc|1tmc]]</td></tr>
-<tr><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=9606 Homo sapiens])</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=9606 Homo sapiens])</td></tr>
-<tr><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='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><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1r49 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1r49 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1r49 RCSB], [http://www.ebi.ac.uk/pdbsum/1r49 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=1r49 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1r49 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1r49 RCSB], [http://www.ebi.ac.uk/pdbsum/1r49 PDBsum]</span></td></tr>
-<table>
+</table>
 == Disease ==
 [[http://www.uniprot.org/uniprot/TOP1_HUMAN TOP1_HUMAN]] Note=A chromosomal aberration involving TOP1 is found in a form of therapy-related myelodysplastic syndrome. Translocation t(11;20)(p15;q11) with NUP98.
@@ Line 39: / Line 39: @@
 [[Category: DNA topoisomerase]]
 [[Category: Homo sapiens]]
-[[Category: Champoux, J J.]]
+[[Category: Champoux, J J]]
-[[Category: Hol, W G.]]
+[[Category: Hol, W G]]
-[[Category: Interthal, H.]]
+[[Category: Interthal, H]]
-[[Category: Quigley, P M.]]
+[[Category: Quigley, P M]]
 [[Category: Dna]]
 [[Category: Isomerase-dna complex]]
 [[Category: Protein]]
 [[Category: Topoisomerase i]]

1r49

From Proteopedia

Revision as of 07:19, 6 January 2015

Human topoisomerase I (Topo70) double mutant K532R/Y723F

Structural highlights

Disease

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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