10596-21-1Relevant academic research and scientific papers
Transition state in DNA polymerase β Catalysis: Rate-Limiting chemistry altered by base-pair configuration
Oertell, Keriann,Chamberlain, Brian T.,Wu, Yue,Ferri, Elena,Kashemirov, Boris A.,Beard, William A.,Wilson, Samuel H.,McKenna, Charles E.,Goodman, Myron F.
, p. 1842 - 1848 (2014)
Kinetics studies of dNTP analogues having pyrophosphate-mimicking β,β-pCXYp leaving groups with variable X and Y substitution reveal striking differences in the chemical transition-state energy for DNA polymerase β that depend on all aspects of base-pairing configurations, including whether the incoming dNTP is a purine or pyrimidine and if base-pairings are right (T*A and G*C) or wrong (T*G and G*T). Br?nsted plots of the catalytic rate constant (log(kpol)) versus pKa4 for the leaving group exhibit linear free energy relationships (LFERs) with negative slopes ranging from -0.6 to -2.0, consistent with chemical rate-determining transition-states in which the active-site adjusts to charge-stabilization demand during chemistry depending on base-pair configuration. The Br?nsted slopes as well as the intercepts differ dramatically and provide the first direct evidence that dNTP base recognition by the enzyme-primer-template complex triggers a conformational change in the catalytic region of the active-site that significantly modifies the rate-determining chemical step.
