1lpq
From Proteopedia
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|PDB= 1lpq |SIZE=350|CAPTION= <scene name='initialview01'>1lpq</scene>, resolution 3.14Å | |PDB= 1lpq |SIZE=350|CAPTION= <scene name='initialview01'>1lpq</scene>, resolution 3.14Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= | + | |LIGAND= <scene name='pdbligand=8OG:8-OXO-2'-DEOXY-GUANOSINE-5'-MONOPHOSPHATE'>8OG</scene>, <scene name='pdbligand=DA:2'-DEOXYADENOSINE-5'-MONOPHOSPHATE'>DA</scene>, <scene name='pdbligand=DC:2'-DEOXYCYTIDINE-5'-MONOPHOSPHATE'>DC</scene>, <scene name='pdbligand=DG:2'-DEOXYGUANOSINE-5'-MONOPHOSPHATE'>DG</scene>, <scene name='pdbligand=DT:THYMIDINE-5'-MONOPHOSPHATE'>DT</scene> |
| - | |ACTIVITY= [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] | + | |ACTIVITY= <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> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1a31|1A31]], [[1a35|1A35]], [[1a36|1A36]], [[1ej9|1EJ9]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1lpq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lpq OCA], [http://www.ebi.ac.uk/pdbsum/1lpq PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1lpq RCSB]</span> | ||
}} | }} | ||
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==Overview== | ==Overview== | ||
7,8-Dihydro-8-oxoguanine (8-oxoG) is the most common form of oxidative DNA damage in human cells. Biochemical studies have shown that 8-oxoG decreases the DNA cleavage activity of human topoisomerase I, an enzyme vital to DNA metabolism and stability. We present the 3.1-A crystal structure of human topoisomerase I in noncovalent complex with a DNA oligonucleotide containing 8-oxoG at the +1 position in the scissile strand. We find that 8-oxoG reorganizes the active site of human topoisomerase I into an inactive conformation relative to the structures of topoisomerase I-DNA complexes elucidated previously. The catalytic Tyr-723-Phe rotates away from the DNA cleavage site and packs into the body of the molecule. A second active-site residue, Arg-590, becomes disordered and is not observed in the structure. The docked, inactive conformation of Tyr-723-Phe is reminiscent of the related tyrosine recombinase family of integrases and recombinases, suggesting a common regulatory mechanism. We propose that human topoisomerase I binds to DNA first in an inactive conformation and then rearranges its active site for catalysis. 8-OxoG appears to impact topoisomerase I by stabilizing the inactive, DNA-bound state. | 7,8-Dihydro-8-oxoguanine (8-oxoG) is the most common form of oxidative DNA damage in human cells. Biochemical studies have shown that 8-oxoG decreases the DNA cleavage activity of human topoisomerase I, an enzyme vital to DNA metabolism and stability. We present the 3.1-A crystal structure of human topoisomerase I in noncovalent complex with a DNA oligonucleotide containing 8-oxoG at the +1 position in the scissile strand. We find that 8-oxoG reorganizes the active site of human topoisomerase I into an inactive conformation relative to the structures of topoisomerase I-DNA complexes elucidated previously. The catalytic Tyr-723-Phe rotates away from the DNA cleavage site and packs into the body of the molecule. A second active-site residue, Arg-590, becomes disordered and is not observed in the structure. The docked, inactive conformation of Tyr-723-Phe is reminiscent of the related tyrosine recombinase family of integrases and recombinases, suggesting a common regulatory mechanism. We propose that human topoisomerase I binds to DNA first in an inactive conformation and then rearranges its active site for catalysis. 8-OxoG appears to impact topoisomerase I by stabilizing the inactive, DNA-bound state. | ||
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| - | ==Disease== | ||
| - | Known disease associated with this structure: DNA topoisomerase I, camptothecin-resistant OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=126420 126420]] | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: protein-dna complex]] | [[Category: protein-dna complex]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:05:49 2008'' |
Revision as of 19:05, 30 March 2008
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| , resolution 3.14Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , , | ||||||
| Activity: | DNA topoisomerase, with EC number 5.99.1.2 | ||||||
| Related: | 1A31, 1A35, 1A36, 1EJ9
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Human DNA Topoisomerase I (70 Kda) In Non-Covalent Complex With A 22 Base Pair DNA Duplex Containing an 8-oxoG Lesion
Overview
7,8-Dihydro-8-oxoguanine (8-oxoG) is the most common form of oxidative DNA damage in human cells. Biochemical studies have shown that 8-oxoG decreases the DNA cleavage activity of human topoisomerase I, an enzyme vital to DNA metabolism and stability. We present the 3.1-A crystal structure of human topoisomerase I in noncovalent complex with a DNA oligonucleotide containing 8-oxoG at the +1 position in the scissile strand. We find that 8-oxoG reorganizes the active site of human topoisomerase I into an inactive conformation relative to the structures of topoisomerase I-DNA complexes elucidated previously. The catalytic Tyr-723-Phe rotates away from the DNA cleavage site and packs into the body of the molecule. A second active-site residue, Arg-590, becomes disordered and is not observed in the structure. The docked, inactive conformation of Tyr-723-Phe is reminiscent of the related tyrosine recombinase family of integrases and recombinases, suggesting a common regulatory mechanism. We propose that human topoisomerase I binds to DNA first in an inactive conformation and then rearranges its active site for catalysis. 8-OxoG appears to impact topoisomerase I by stabilizing the inactive, DNA-bound state.
About this Structure
1LPQ is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
8-Oxoguanine rearranges the active site of human topoisomerase I., Lesher DT, Pommier Y, Stewart L, Redinbo MR, Proc Natl Acad Sci U S A. 2002 Sep 17;99(19):12102-7. Epub 2002 Sep 3. PMID:12209008
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