2pfp: Difference between revisions
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==Overview== | ==Overview== | ||
The incorporation of dNMPs into DNA by polymerases involves a phosphoryl | The incorporation of dNMPs into DNA by polymerases involves a phosphoryl transfer reaction hypothesized to require two divalent metal ions. Here we investigate this hypothesis using as a model human DNA polymerase lambda (Pol lambda), an enzyme suggested to be activated in vivo by manganese. We report the crystal structures of four complexes of human Pol lambda. In a 1.9 A structure of Pol lambda containing a 3'-OH and the non-hydrolyzable analog dUpnpp, a non-catalytic Na+ ion occupies the site for metal A and the ribose of the primer-terminal nucleotide is found in a conformation that positions the acceptor 3'-OH out of line with the alpha-phosphate and the bridging oxygen of the pyrophosphate leaving group. Soaking this crystal in MnCl2 yielded a 2.0 A structure with Mn2+ occupying the site for metal A. In the presence of Mn2+, the conformation of the ribose is C3'-endo and the 3'-oxygen is in line with the leaving oxygen, at a distance from the phosphorus atom of the alpha-phosphate (3.69 A) consistent with and supporting a catalytic mechanism involving two divalent metal ions. Finally, soaking with MnCl2 converted a pre-catalytic Pol lambda/Na+ complex with unreacted dCTP in the active site into a product complex via catalysis in the crystal. These data provide pre- and post-transition state information and outline in a single crystal the pathway for the phosphoryl transfer reaction carried out by DNA polymerases. | ||
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
Role of the catalytic metal during polymerization by DNA polymerase lambda., Garcia-Diaz M, Bebenek K, Krahn JM, Pedersen LC, Kunkel TA, DNA Repair (Amst). 2007 | Role of the catalytic metal during polymerization by DNA polymerase lambda., Garcia-Diaz M, Bebenek K, Krahn JM, Pedersen LC, Kunkel TA, DNA Repair (Amst). 2007 Sep 1;6(9):1333-40. Epub 2007 May 1. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17475573 17475573] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Bebenek, K.]] | [[Category: Bebenek, K.]] | ||
[[Category: Garcia-Diaz, M.]] | [[Category: Garcia-Diaz, M.]] | ||
[[Category: Krahn, J | [[Category: Krahn, J M.]] | ||
[[Category: Kunkel, T | [[Category: Kunkel, T A.]] | ||
[[Category: Pedersen, L | [[Category: Pedersen, L C.]] | ||
[[Category: DCP]] | [[Category: DCP]] | ||
[[Category: MG]] | [[Category: MG]] | ||
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[[Category: phosphoryl transfer reaction]] | [[Category: phosphoryl transfer reaction]] | ||
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Revision as of 19:29, 21 February 2008
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DNA Polymerase lambda in complex with DNA and dCTP
OverviewOverview
The incorporation of dNMPs into DNA by polymerases involves a phosphoryl transfer reaction hypothesized to require two divalent metal ions. Here we investigate this hypothesis using as a model human DNA polymerase lambda (Pol lambda), an enzyme suggested to be activated in vivo by manganese. We report the crystal structures of four complexes of human Pol lambda. In a 1.9 A structure of Pol lambda containing a 3'-OH and the non-hydrolyzable analog dUpnpp, a non-catalytic Na+ ion occupies the site for metal A and the ribose of the primer-terminal nucleotide is found in a conformation that positions the acceptor 3'-OH out of line with the alpha-phosphate and the bridging oxygen of the pyrophosphate leaving group. Soaking this crystal in MnCl2 yielded a 2.0 A structure with Mn2+ occupying the site for metal A. In the presence of Mn2+, the conformation of the ribose is C3'-endo and the 3'-oxygen is in line with the leaving oxygen, at a distance from the phosphorus atom of the alpha-phosphate (3.69 A) consistent with and supporting a catalytic mechanism involving two divalent metal ions. Finally, soaking with MnCl2 converted a pre-catalytic Pol lambda/Na+ complex with unreacted dCTP in the active site into a product complex via catalysis in the crystal. These data provide pre- and post-transition state information and outline in a single crystal the pathway for the phosphoryl transfer reaction carried out by DNA polymerases.
About this StructureAbout this Structure
2PFP is a Single protein structure of sequence from Homo sapiens with , and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Role of the catalytic metal during polymerization by DNA polymerase lambda., Garcia-Diaz M, Bebenek K, Krahn JM, Pedersen LC, Kunkel TA, DNA Repair (Amst). 2007 Sep 1;6(9):1333-40. Epub 2007 May 1. PMID:17475573
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