1tva
From Proteopedia
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HUMAN DNA POLYMERASE BETA COMPLEXED WITH NICKED DNA CONTAINING A MISMATCHED TEMPLATE THYMIDINE AND INCOMING CYTIDINE
Overview
DNA polymerases generally select the correct nucleotide from a pool of, structurally similar molecules to preserve Watson-Crick base-pairing, rules. We report the structure of DNA polymerase beta with DNA mismatches, situated in the polymerase active site. This was achieved by using nicked, product DNA that traps the mispair (template-primer, A-C or T-C) in the, nascent base pair binding pocket. The structure of each mispair complex, indicates that the bases do not form hydrogen bonds with one another, but, form a staggered arrangement where the bases of the mispair partially, overlap. This prevents closure/opening of the N subdomain that is believed, to be required for catalytic cycling. The partially open conformation of, the N subdomain results in distinct hydrogen bonding networks that are, unique for each mispair. These structures define diverse molecular aspects, of misinsertion that are consistent with the induced-fit model for, substrate specificity.
About this Structure
1TVA is a Single protein structure of sequence from Homo sapiens with NA, MG and PO4 as ligands. Active as DNA-directed DNA polymerase, with EC number 2.7.7.7 Full crystallographic information is available from OCA.
Reference
Structural insights into DNA polymerase beta deterrents for misincorporation support an induced-fit mechanism for fidelity., Krahn JM, Beard WA, Wilson SH, Structure. 2004 Oct;12(10):1823-32. PMID:15458631
Page seeded by OCA on Mon Nov 12 19:28:25 2007
