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≈ATP≈CTP