2py5
From Proteopedia
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Phi29 DNA polymerase complexed with single-stranded DNA
Overview
Replicative DNA polymerases (DNAPs) move along template DNA in a processive manner. The structural basis of the mechanism of translocation has been better studied in the A-family of polymerases than in the B-family of replicative polymerases. To address this issue, we have determined the X-ray crystal structures of phi29 DNAP, a member of the protein-primed subgroup of the B-family of polymerases, complexed with primer-template DNA in the presence or absence of the incoming nucleoside triphosphate, the pre- and post-translocated states, respectively. Comparison of these structures reveals a mechanism of translocation that appears to be facilitated by the coordinated movement of two conserved tyrosine residues into the insertion site. This differs from the mechanism employed by the A-family polymerases, in which a conserved tyrosine moves into the templating and insertion sites during the translocation step. Polymerases from the two families also interact with downstream single-stranded template DNA in very different ways.
About this Structure
2PY5 is a Single protein structure of sequence from Vibrio phage f237 with as ligand. Active as DNA-directed DNA polymerase, with EC number 2.7.7.7 Full crystallographic information is available from OCA.
Reference
Structures of phi29 DNA polymerase complexed with substrate: the mechanism of translocation in B-family polymerases., Berman AJ, Kamtekar S, Goodman JL, Lazaro JM, de Vega M, Blanco L, Salas M, Steitz TA, EMBO J. 2007 Jul 25;26(14):3494-505. Epub 2007 Jul 5. PMID:17611604
Page seeded by OCA on Thu Feb 21 18:34:11 2008
