1d6m
From Proteopedia
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| - | [[Image:1d6m.gif|left|200px]] | + | [[Image:1d6m.gif|left|200px]] |
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| - | '''CRYSTAL STRUCTURE OF E. COLI DNA TOPOISOMERASE III''' | + | {{Structure |
| + | |PDB= 1d6m |SIZE=350|CAPTION= <scene name='initialview01'>1d6m</scene>, resolution 3.00Å | ||
| + | |SITE= | ||
| + | |LIGAND= | ||
| + | |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] | ||
| + | |GENE= | ||
| + | }} | ||
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| + | '''CRYSTAL STRUCTURE OF E. COLI DNA TOPOISOMERASE III''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1D6M is a [ | + | 1D6M is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D6M OCA]. |
==Reference== | ==Reference== | ||
| - | The structure of Escherichia coli DNA topoisomerase III., Mondragon A, DiGate R, Structure. 1999 Nov 15;7(11):1373-83. PMID:[http:// | + | The structure of Escherichia coli DNA topoisomerase III., Mondragon A, DiGate R, Structure. 1999 Nov 15;7(11):1373-83. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10574789 10574789] |
[[Category: DNA topoisomerase]] | [[Category: DNA topoisomerase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
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[[Category: dna topoisomerase]] | [[Category: dna topoisomerase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:33:33 2008'' |
Revision as of 08:33, 20 March 2008
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| , resolution 3.00Å | |||||||
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| Activity: | DNA topoisomerase, with EC number 5.99.1.2 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF E. COLI DNA TOPOISOMERASE III
Overview
BACKGROUND: DNA topoisomerases are enzymes that change the topology of DNA. Type IA topoisomerases transiently cleave one DNA strand in order to pass another strand or strands through the break. In this manner, they can relax negatively supercoiled DNA and catenate and decatenate DNA molecules. Structural information on Escherichia coli DNA topoisomerase III is important for understanding the mechanism of this type of enzyme and for studying the mechanistic differences among different members of the same subfamily. RESULTS: The structure of the intact and fully active E. coli DNA topoisomerase III has been solved to 3.0 A resolution. The structure shows the characteristic fold of the type IA topoisomerases that is formed by four domains, creating a toroidal protein. There is remarkable structural similarity to the 67 kDa N-terminal fragment of E. coli DNA topoisomerase I, although the relative arrangement of the four domains is significantly different. A major difference is the presence of a 17 amino acid insertion in topoisomerase III that protrudes from the side of the central hole and could be involved in the catenation and decatenation reactions. The active site is formed by highly conserved amino acids, but the structural information and existing biochemical and mutagenesis data are still insufficient to assign specific roles to most of them. The presence of a groove in one side of the protein is suggestive of a single-stranded DNA (ssDNA)-binding region. CONCLUSIONS: The structure of E. coli DNA topoisomerase III resembles the structure of E. coli DNA topoisomerase I except for the presence of a positively charged loop that may be involved in catenation and decatenation. A groove on the side of the protein leads to the active site and is likely to be involved in DNA binding. The structure helps to establish the overall mechanism for the type IA subfamily of topoisomerases with greater confidence and expands the structural basis for understanding these proteins.
About this Structure
1D6M is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
The structure of Escherichia coli DNA topoisomerase III., Mondragon A, DiGate R, Structure. 1999 Nov 15;7(11):1373-83. PMID:10574789
Page seeded by OCA on Thu Mar 20 10:33:33 2008
