We use single-molecule FRET and newly-developed D-loop techniques to investigate strand displacement activity of Klenow fragment(exo-)of DNA polymerase I in DNA sequences rich in guanine and cytosine(GC)bases.We find ...We use single-molecule FRET and newly-developed D-loop techniques to investigate strand displacement activity of Klenow fragment(exo-)of DNA polymerase I in DNA sequences rich in guanine and cytosine(GC)bases.We find that there exist in the FRET traces numerous ascending jumps,which are induced by the backsliding of Klenow fragment on DNA chains.Our measurements show that the probability of backsliding is closely related to the GC-richness and d NTP concentration:increasing the GC-richness leads to an increase in the backsliding probability,and increasing the d NTP concentration however leads to a decrease in the backsliding probability.These results provide a new insight into the mechanism of DNA polymerase I.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.12090051)the CAS Key Research Program of Frontier Sciences(Grant Nos.QYZDJSSW-SYS014 and ZDBS-LY-SLH015)the Youth Innovation Promotion Association of CAS(Grant No.2017015)。
文摘We use single-molecule FRET and newly-developed D-loop techniques to investigate strand displacement activity of Klenow fragment(exo-)of DNA polymerase I in DNA sequences rich in guanine and cytosine(GC)bases.We find that there exist in the FRET traces numerous ascending jumps,which are induced by the backsliding of Klenow fragment on DNA chains.Our measurements show that the probability of backsliding is closely related to the GC-richness and d NTP concentration:increasing the GC-richness leads to an increase in the backsliding probability,and increasing the d NTP concentration however leads to a decrease in the backsliding probability.These results provide a new insight into the mechanism of DNA polymerase I.
