2bpf
From Proteopedia
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STRUCTURES OF TERNARY COMPLEXES OF RAT DNA POLYMERASE BETA, A DNA TEMPLATE-PRIMER, AND DDCTP
Overview
Two ternary complexes of rat DNA polymerase beta (pol beta), a DNA, template-primer, and dideoxycytidine triphosphate (ddCTP) have been, determined at 2.9 A and 3.6 A resolution, respectively. ddCTP is the, triphosphate of dideoxycytidine (ddC), a nucleoside analog that targets, the reverse transcriptase of human immunodeficiency virus (HIV) and is at, present used to treat AIDS. Although crystals of the two complexes belong, to different space groups, the structures are similar, suggesting that the, polymerase-DNA-ddCTP interactions are not affected by crystal packing, forces. In the pol beta active site, the attacking 3'-OH of the elongating, primer, the ddCTP phosphates, and two Mg2+ ions are all clustered around, Asp190, Asp192, and Asp256. Two of these residues, Asp190 and Asp256, are, present in the amino acid sequences of all polymerases so far studied and, are also spatially similar in the four polymerases--the Klenow fragment of, Escherichia coli DNA polymerase I, HIV-1 reverse transcriptase, T7 RNA, polymerase, and rat DNA pol beta--whose crystal structures are now known., A two-metal ion mechanism is described for the nucleotidyl transfer, reaction and may apply to all polymerases. In the ternary complex, structures analyzed, pol beta binds to the DNA template-primer in a, different manner from that recently proposed for other polymerase-DNA, models.
About this Structure
2BPF is a Single protein structure of sequence from Rattus norvegicus with MG and DCT as ligands. Full crystallographic information is available from OCA.
Reference
Structures of ternary complexes of rat DNA polymerase beta, a DNA template-primer, and ddCTP., Pelletier H, Sawaya MR, Kumar A, Wilson SH, Kraut J, Science. 1994 Jun 24;264(5167):1891-903. PMID:7516580
Page seeded by OCA on Wed Nov 21 08:52:05 2007
