Structures of DNA-pol β ternary complexes with
monochloro, monobromo and monomethyl
β,γ-CXY dGTP analogues. The
Fo−Fc simulated annealing electron density
omit maps (light blue) contoured at 4σ show electron density for the
corresponding β,γ-dGTP analogue. (a) Both
stereoisomers of β,γ-CHCl-dGTP
(6, 7) are observed in the ternary complex.
The chlorine atoms are purple; the carbon atoms of the
(R)-isomer (6) are yellow while those of the
(S)-isomer (7) are gray. (b) Both
stereoisomers of β,γ-CHBr-dGTP
(8, 9) are observed in the ternary complex.
The bromine atoms are dark red; the carbon atoms of the
(R)-isomer (8) are yellow, while those of the
(S)-isomer (9) are gray. (c) Both
stereoisomers of β,γ-CHCH3-dGTP
(10, 11) are observed in the ternary complex.
The carbon atoms of the (R)-isomer (10) are
gray while those of the (S)-isomer (11) are
yellow.