Halogenated beta,gamma-methylene- and ethylidene-dGTP-DNA ternary complexes with DNA polymerase beta: structural evidence for stereospecific binding of the fluoromethylene analogues.

ABSTRACT: Beta,gamma-fluoromethylene analogues of nucleotides are considered to be useful mimics of the natural substrates, but direct structural evidence defining their active site interactions has not been available, including the influence of the new chiral center introduced at the CHF carbon, as in beta,gamma-fluoromethylene-dGTP, which forms an active site complex with DNA polymerase beta, a repair enzyme that plays an important role in base excision repair (BER) and oncogenesis. We report X-ray crystallographic results for a series of beta,gamma-CXY dGTP analogues, where X,Y = H, F, Cl, Br, and/or CH(3). For all three R/S monofluorinated analogues examined (CHF, 3/4; CCH(3)F, 13/14; CClF 15/16), a single CXF-diastereomer (3, 13, 16) is observed in the active site complex, with the CXF fluorine

SUBMITTER: Batra VK 

PROVIDER: S-EPMC2891752 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature