Pestivirus NS3 (p80) protein possesses RNA helicase activity

Identification and characterization of the RNA helicase activity of Japanese encephalitis virus NS3 protein.

The NS3 protein of Japanese encephalitis virus (JEV) contains motifs typical of RNA helicase/NTPase but no RNA helicase activity has been reported for this protein. To identify and characterize the RNA helicase activity of JEV NS3, a truncated form of the protein with a His-tag was expressed in Escherichia coli and purified. The purified JEV NS3 protein showed an RNA helicase activity, which wa...

Crystal structure and activity of Kunjin virus NS3 helicase; protease and helicase domain assembly in the full length NS3 protein.

Flaviviral NS3 is a multifunctional protein displaying N-terminal protease activity in addition to C-terminal helicase, nucleoside 5'-triphosphatase (NTPase), and 5'-terminal RNA triphosphatase (RTPase) activities. NS3 is held to support the separation of RNA daughter and template strands during viral replication. In addition, NS3 assists the initiation of replication by unwinding the RNA secon...

Modulation of the hepatitis C virus RNA-dependent RNA polymerase activity by the NS3 helicase and the NS4B membrane protein

Stimulation of hepatitis C virus (HCV) nonstructural protein 3 (NS3) helicase activity by the NS3 protease domain and by HCV RNA-dependent RNA polymerase.

Hepatitis C virus (HCV) nonstructural protein 3 (NS3) possesses multiple enzyme activities. The N-terminal one-third of NS3 primarily functions as a serine protease, while the remaining two-thirds of NS3 serve as a helicase and nucleoside triphosphatase. Whether the multiple enzyme activities of NS3 are functionally interdependent and/or modulated by other viral NS proteins remains unclear. We ...

X-ray structure of the pestivirus NS3 helicase and its conformation in solution.

UNLABELLED Pestiviruses form a genus in the Flaviviridae family of small enveloped viruses with a positive-sense single-stranded RNA genome. Viral replication in this family requires the activity of a superfamily 2 RNA helicase contained in the C-terminal domain of nonstructural protein 3 (NS3). NS3 features two conserved RecA-like domains (D1 and D2) with ATPase activity, plus a third domain (...