1e0k
From Proteopedia
(New page: 200px<br /><applet load="1e0k" size="450" color="white" frame="true" align="right" spinBox="true" caption="1e0k, resolution 3.30Å" /> '''GP4D HELICASE FROM P...) |
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| - | [[Image:1e0k.jpg|left|200px]]<br /><applet load="1e0k" size=" | + | [[Image:1e0k.jpg|left|200px]]<br /><applet load="1e0k" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1e0k, resolution 3.30Å" /> | caption="1e0k, resolution 3.30Å" /> | ||
'''GP4D HELICASE FROM PHAGE T7'''<br /> | '''GP4D HELICASE FROM PHAGE T7'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We have determined the crystal structure of an active, hexameric fragment | + | We have determined the crystal structure of an active, hexameric fragment of the gene 4 helicase from bacteriophage T7. The structure reveals how subunit contacts stabilize the hexamer. Deviation from expected six-fold symmetry of the hexamer indicates that the structure is of an intermediate on the catalytic pathway. The structural consequences of the asymmetry suggest a "binding change" mechanism to explain how cooperative binding and hydrolysis of nucleotides are coupled to conformational changes in the ring that most likely accompany duplex unwinding. The structure of a complex with a nonhydrolyzable ATP analog provides additional evidence for this hypothesis, with only four of the six possible nucleotide binding sites being occupied in this conformation of the hexamer. This model suggests a mechanism for DNA translocation. |
==About this Structure== | ==About this Structure== | ||
| - | 1E0K is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t7 Bacteriophage t7]. Full crystallographic information is available from [http:// | + | 1E0K is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t7 Bacteriophage t7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E0K OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Ellenberger, T.]] | [[Category: Ellenberger, T.]] | ||
| - | [[Category: Sawaya, M | + | [[Category: Sawaya, M R.]] |
| - | [[Category: Singleton, M | + | [[Category: Singleton, M R.]] |
| - | [[Category: Wigley, D | + | [[Category: Wigley, D B.]] |
[[Category: atpase]] | [[Category: atpase]] | ||
[[Category: dna replication]] | [[Category: dna replication]] | ||
[[Category: helicase]] | [[Category: helicase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:22:30 2008'' |
Revision as of 10:22, 21 February 2008
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GP4D HELICASE FROM PHAGE T7
Overview
We have determined the crystal structure of an active, hexameric fragment of the gene 4 helicase from bacteriophage T7. The structure reveals how subunit contacts stabilize the hexamer. Deviation from expected six-fold symmetry of the hexamer indicates that the structure is of an intermediate on the catalytic pathway. The structural consequences of the asymmetry suggest a "binding change" mechanism to explain how cooperative binding and hydrolysis of nucleotides are coupled to conformational changes in the ring that most likely accompany duplex unwinding. The structure of a complex with a nonhydrolyzable ATP analog provides additional evidence for this hypothesis, with only four of the six possible nucleotide binding sites being occupied in this conformation of the hexamer. This model suggests a mechanism for DNA translocation.
About this Structure
1E0K is a Single protein structure of sequence from Bacteriophage t7. Full crystallographic information is available from OCA.
Reference
Crystal structure of T7 gene 4 ring helicase indicates a mechanism for sequential hydrolysis of nucleotides., Singleton MR, Sawaya MR, Ellenberger T, Wigley DB, Cell. 2000 Jun 9;101(6):589-600. PMID:10892646
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