PMID- 20071563
OWN - NLM
STAT- MEDLINE
DCOM- 20100330
LR  - 20211020
IS  - 1098-5514 (Electronic)
IS  - 0022-538X (Print)
IS  - 0022-538X (Linking)
VI  - 84
IP  - 7
DP  - 2010 Apr
TI  - NTPase and 5' to 3' RNA duplex-unwinding activities of the hepatitis E virus 
      helicase domain.
PG  - 3595-602
LID - 10.1128/JVI.02130-09 [doi]
AB  - Hepatitis E virus (HEV) is a causative agent of acute hepatitis, and it is the 
      sole member of the genus Hepevirus in the family Hepeviridae. The open reading 
      frame 1 (ORF1) protein of HEV encodes nonstructural polyprotein with putative 
      domains for methyltransferase, cysteine protease, helicase and RNA-dependent RNA 
      polymerase. It is not yet known whether ORF1 functions as a single protein with 
      multiple domains or is processed to form separate functional units. On the basis 
      of amino acid conserved motifs, HEV helicase has been grouped into helicase 
      superfamily 1 (SF-1). In order to examine the RNA helicase activity of the 
      NTPase/helicase domain of HEV, the region (amino acids 960 to 1204) was cloned 
      and expressed as histidine-tagged protein in Escherichia coli (HEV Hel) and 
      purified. HEV Hel exhibited NTPase and RNA unwinding activities. Enzyme 
      hydrolyzed all rNTPs efficiently, dATP and dCTP with moderate efficiency, while 
      it showed less hydrolysis of dGTP and dTTP. Enzyme showed unwinding of only RNA 
      duplexes with 5' overhangs showing 5'-to-3' polarity. We also expressed and 
      purified two HEV Hel mutants. Helicase mutant I, with substitution in the 
      nucleotide-binding motif I (GKS to GAS), showed 30% ATPase activity. Helicase 
      mutant II, with substitutions in the Mg(2+) binding motif II (DEAP to AAAP), 
      showed 50% ATPase activity. Both mutants completely lost ability to unwind RNA 
      duplexes with 5' overhangs. These findings represent the first report 
      demonstrating NTPase/RNA helicase activity of the helicase domain of HEV ORF1.
FAU - Karpe, Yogesh A
AU  - Karpe YA
AD  - Hepatitis Division, National Institute of Virology, Microbial Containment 
      Complex, Sus Road, Pashan, Pune, India 411021, USA.
FAU - Lole, Kavita S
AU  - Lole KS
LA  - eng
PT  - Journal Article
DEP - 20100113
PL  - United States
TA  - J Virol
JT  - Journal of virology
JID - 0113724
RN  - 0 (RNA, Viral)
RN  - EC 3.6.1.- (Adenosine Triphosphatases)
RN  - EC 3.6.1.15 (Nucleoside-Triphosphatase)
RN  - EC 3.6.4.13 (RNA Helicases)
SB  - IM
MH  - Adenosine Triphosphatases/metabolism
MH  - Hepatitis E virus/*enzymology
MH  - Nucleoside-Triphosphatase/chemistry/isolation & purification/*metabolism
MH  - Protein Structure, Tertiary
MH  - RNA Helicases/chemistry/isolation & purification/*metabolism
MH  - RNA, Viral/*chemistry
PMC - PMC2838093
EDAT- 2010/01/15 06:00
MHDA- 2010/03/31 06:00
PMCR- 2010/10/01
CRDT- 2010/01/15 06:00
PHST- 2010/01/15 06:00 [entrez]
PHST- 2010/01/15 06:00 [pubmed]
PHST- 2010/03/31 06:00 [medline]
PHST- 2010/10/01 00:00 [pmc-release]
AID - JVI.02130-09 [pii]
AID - 2130-09 [pii]
AID - 10.1128/JVI.02130-09 [doi]
PST - ppublish
SO  - J Virol. 2010 Apr;84(7):3595-602. doi: 10.1128/JVI.02130-09. Epub 2010 Jan 13.