Analysis of Nucleoside Triphosphate Hydrolysis by Middle East Respiratory Syndrome Coronavirus Helicase

摘要

The purpose of this study is to measure the nucleoside triphosphate(NTP)hydrolysis by Middle East Respiratory Syndrome coronavirus(MERS-CoV)helicase in the presence of different types of nucleic acids(NAs)for the determination of the optimal condition of hydrolysis activity.The steady-state NTP hydrolysis analysis demonstrated that the MERS-CoV helicase only(and considerably)hydrolyzed the ATP in the presence of poly(U).On the contrary,only UTP was considerably hydrolyzed in the presence of poly(C).When we used the DNAs as a substrate,the single-stranded M13 DNA considerably stimulated the ATP and UTP hydrolysis.However,the ATP hydrolysis was not detected in the presence of ds DNA.The pH-dependent ATP hydrolysis analysis demonstrated that the helicase optimally hydrolyzed ATP at a pH value of 7.0.The ATP hydrolysis was also performed in the presence of four different kinds of divalent cations,which demonstrated that only Mg~(2+)ions stimulated the ATP hydrolysis activity.