Steady-state NTPase activity of Dengue virus NS3: number of catalytic sites, nucleotide specificity and activation by ssRNA.

ABSTRACT: Dengue virus nonstructural protein 3 (NS3) unwinds double stranded RNA driven by the free energy derived from the hydrolysis of nucleoside triphosphates. This paper presents the first systematic and quantitative characterization of the steady-state NTPase activity of DENV NS3 and their interaction with ssRNA. Substrate curves for ATP, GTP, CTP and UTP were obtained, and the specificity order for these nucleotides - evaluated as the ratio (kcat /KM )- was GTP[Formula: see text]ATP[Formula: see text]CTP [Formula: see text] UTP, which showed that NS3 have poor ability to discriminate between different NTPs. Competition experiments between the four substrates indicated that all of them are hydrolyzed in one and the same catalytic site of the enzyme. The effect of ssRNA on the ATPase activity o

SUBMITTER: Incicco JJ 

PROVIDER: S-EPMC3602377 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature