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1zi0
From Proteopedia
(New page: 200px<br /><applet load="1zi0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zi0, resolution 2.60Å" /> '''A Superhelical Spira...) |
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| - | [[Image:1zi0.gif|left|200px]]<br /><applet load="1zi0" size=" | + | [[Image:1zi0.gif|left|200px]]<br /><applet load="1zi0" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1zi0, resolution 2.60Å" /> | caption="1zi0, resolution 2.60Å" /> | ||
'''A Superhelical Spiral in Escherichia coli DNA Gyrase A C-terminal Domain Imparts Unidirectional Supercoiling Bias'''<br /> | '''A Superhelical Spiral in Escherichia coli DNA Gyrase A C-terminal Domain Imparts Unidirectional Supercoiling Bias'''<br /> | ||
==Overview== | ==Overview== | ||
| - | DNA gyrase is unique among type II topoisomerases in that its DNA | + | DNA gyrase is unique among type II topoisomerases in that its DNA supercoiling activity is unidirectional. The C-terminal domain of the gyrase A subunit (GyrA-CTD) is required for this supercoiling bias. We report here the x-ray structure of the Escherichia coli GyrA-CTD (Protein Data Bank code 1ZI0). The E. coli GyrA-CTD adopts a circular-shaped beta-pinwheel fold first seen in the Borrelia burgdorferi GyrA-CTD. However, whereas the B. burgdorferi GyrA-CTD is flat, the E. coli GyrA-CTD is spiral. DNA relaxation assays reveal that the E. coli GyrA-CTD wraps DNA inducing substantial (+) superhelicity, while the B. burgdorferi GyrA-CTD introduces a more modest (+) superhelicity. The observation of a superhelical spiral in the present structure and that of the Bacillus stearothermophilus ParC-CTD structure suggests unexpected similarities in substrate selectivity between gyrase and Topo IV enzymes. We propose a model wherein the right-handed ((+) solenoidal) wrapping of DNA around the E. coli GyrA-CTD enforces unidirectional (-) DNA supercoiling. |
==About this Structure== | ==About this Structure== | ||
| - | 1ZI0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/DNA_topoisomerase_(ATP-hydrolyzing) DNA topoisomerase (ATP-hydrolyzing)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.99.1.3 5.99.1.3] Full crystallographic information is available from [http:// | + | 1ZI0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/DNA_topoisomerase_(ATP-hydrolyzing) DNA topoisomerase (ATP-hydrolyzing)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.99.1.3 5.99.1.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZI0 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Graybosch, D | + | [[Category: Graybosch, D M.]] |
| - | [[Category: Huetsch, J | + | [[Category: Huetsch, J C.]] |
| - | [[Category: Ruthenburg, A | + | [[Category: Ruthenburg, A J.]] |
| - | [[Category: Verdine, G | + | [[Category: Verdine, G L.]] |
[[Category: beta pinwheel; gyrase; topoisomerase; spiralling beta pinwheel; dna wrapping]] | [[Category: beta pinwheel; gyrase; topoisomerase; spiralling beta pinwheel; dna wrapping]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:15:43 2008'' |
Revision as of 14:15, 21 February 2008
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A Superhelical Spiral in Escherichia coli DNA Gyrase A C-terminal Domain Imparts Unidirectional Supercoiling Bias
Overview
DNA gyrase is unique among type II topoisomerases in that its DNA supercoiling activity is unidirectional. The C-terminal domain of the gyrase A subunit (GyrA-CTD) is required for this supercoiling bias. We report here the x-ray structure of the Escherichia coli GyrA-CTD (Protein Data Bank code 1ZI0). The E. coli GyrA-CTD adopts a circular-shaped beta-pinwheel fold first seen in the Borrelia burgdorferi GyrA-CTD. However, whereas the B. burgdorferi GyrA-CTD is flat, the E. coli GyrA-CTD is spiral. DNA relaxation assays reveal that the E. coli GyrA-CTD wraps DNA inducing substantial (+) superhelicity, while the B. burgdorferi GyrA-CTD introduces a more modest (+) superhelicity. The observation of a superhelical spiral in the present structure and that of the Bacillus stearothermophilus ParC-CTD structure suggests unexpected similarities in substrate selectivity between gyrase and Topo IV enzymes. We propose a model wherein the right-handed ((+) solenoidal) wrapping of DNA around the E. coli GyrA-CTD enforces unidirectional (-) DNA supercoiling.
About this Structure
1ZI0 is a Single protein structure of sequence from Escherichia coli. Active as DNA topoisomerase (ATP-hydrolyzing), with EC number 5.99.1.3 Full crystallographic information is available from OCA.
Reference
A superhelical spiral in the Escherichia coli DNA gyrase A C-terminal domain imparts unidirectional supercoiling bias., Ruthenburg AJ, Graybosch DM, Huetsch JC, Verdine GL, J Biol Chem. 2005 Jul 15;280(28):26177-84. Epub 2005 May 15. PMID:15897198
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