The protease domain increases the translocation stepping efficiency of the hepatitis C virus NS3-4A helicase.

ABSTRACT: Hepatitis C virus (HCV) NS3 protein has two enzymatic activities of helicase and protease that are essential for viral replication. The helicase separates the strands of DNA and RNA duplexes using the energy from ATP hydrolysis. To understand how ATP hydrolysis is coupled to helicase movement, we measured the single turnover helicase translocation-dissociation kinetics and the pre-steady-state P(i) release kinetics on single-stranded RNA and DNA substrates of different lengths. The parameters of stepping were determined from global fitting of the two types of kinetic measurements into a computational model that describes translocation as a sequence of coupled hydrolysis-stepping reactions. Our results show that the HCV helicase moves with a faster rate on single stranded RNA than on DNA. T

SUBMITTER: Rajagopal V 

PROVIDER: S-EPMC2878546 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature