The effect of mechanical tension on DNA polymerase activity studied with a two-state model

摘要: Single-molecule experiments revealed that the replication rate of T7 DNA polymerase has a peak value at tension of about 5.5 pN. However, the mechanism leading to this peak has only been partially investigated. Here, we present a two-state model to investigate the effect of mechanical tension on DNApolymerase activity. The model consists of polymerase and exonuclease. The polymerase's kinetic pathway has been simplified into Michaelis-Menten formwith two steps. One is the conformational change from "open" to "close". The other is the base-stacking. The results are in good agreement with experimental observations. We also predict that the tension on template is beneficial to the fidelity of DNA replication.