2pjr: Difference between revisions
New page: left|200px<br /><applet load="2pjr" size="450" color="white" frame="true" align="right" spinBox="true" caption="2pjr, resolution 2.9Å" /> '''HELICASE PRODUCT COMP... |
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[[Image:2pjr.gif|left|200px]]<br /><applet load="2pjr" size=" | [[Image:2pjr.gif|left|200px]]<br /><applet load="2pjr" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2pjr, resolution 2.9Å" /> | caption="2pjr, resolution 2.9Å" /> | ||
'''HELICASE PRODUCT COMPLEX'''<br /> | '''HELICASE PRODUCT COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
We have determined two different structures of PcrA DNA helicase complexed | We have determined two different structures of PcrA DNA helicase complexed with the same single strand tailed DNA duplex, providing snapshots of different steps on the catalytic pathway. One of the structures is of a complex with a nonhydrolyzable analog of ATP and is thus a "substrate" complex. The other structure contains a bound sulphate ion that sits in a position equivalent to that occupied by the phosphate ion produced after ATP hydrolysis, thereby mimicking a "product" complex. In both complexes, the protein is monomeric. Large and distinct conformational changes occur on binding DNA and the nucleotide cofactor. Taken together, these structures provide evidence against an "active rolling" model for helicase action but are instead consistent with an "inchworm" mechanism. | ||
==About this Structure== | ==About this Structure== | ||
2PJR is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 2PJR is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PJR OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Geobacillus stearothermophilus]] | [[Category: Geobacillus stearothermophilus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Dillingham, M | [[Category: Dillingham, M S.]] | ||
[[Category: Soultanas, P.]] | [[Category: Soultanas, P.]] | ||
[[Category: Subramanya, H | [[Category: Subramanya, H S.]] | ||
[[Category: Velankar, S | [[Category: Velankar, S S.]] | ||
[[Category: Wigley, D | [[Category: Wigley, D B.]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
[[Category: dna]] | [[Category: dna]] | ||
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[[Category: product complex]] | [[Category: product complex]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:30:10 2008'' | ||
Revision as of 19:30, 21 February 2008
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HELICASE PRODUCT COMPLEX
OverviewOverview
We have determined two different structures of PcrA DNA helicase complexed with the same single strand tailed DNA duplex, providing snapshots of different steps on the catalytic pathway. One of the structures is of a complex with a nonhydrolyzable analog of ATP and is thus a "substrate" complex. The other structure contains a bound sulphate ion that sits in a position equivalent to that occupied by the phosphate ion produced after ATP hydrolysis, thereby mimicking a "product" complex. In both complexes, the protein is monomeric. Large and distinct conformational changes occur on binding DNA and the nucleotide cofactor. Taken together, these structures provide evidence against an "active rolling" model for helicase action but are instead consistent with an "inchworm" mechanism.
About this StructureAbout this Structure
2PJR is a Protein complex structure of sequences from Geobacillus stearothermophilus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of complexes of PcrA DNA helicase with a DNA substrate indicate an inchworm mechanism., Velankar SS, Soultanas P, Dillingham MS, Subramanya HS, Wigley DB, Cell. 1999 Apr 2;97(1):75-84. PMID:10199404
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