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 was dependent on divalent cations and ATP. An Asp-285-to-Ala substitution in motif II of the JEV NS3 protein abolished the ATPase and RNA helicase activities. These results indicate that the C-terminal 457 residues are sufficient to exhibit the RNA helicase activity of JEV NS3.
Utama
A
A
Department of Bioprocessing, Faculty of Agriculture, Gifu University, 1-1 Yanagido, Gifu, Japan.
Shimizu
H
H
Morikawa
S
S
Hasebe
F
F
Morita
K
K
Igarashi
A
A
Hatsu
M
M
Takamizawa
K
K
Miyamura
T
T
D000251:Adenosine Triphosphatases / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D015870:Gene Expression; D016297:Mutagenesis, Site-Directed; D020365:RNA Helicases / Q000737:chemistry*; D012697:Serine Endopeptidases; D013379:Substrate Specificity; D017361:Viral Nonstructural Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000251:Adenosine Triphosphatases; D020365:RNA Helicases; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C060028:NS3 protein, flavivirus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases