| NTPase and 5' to 3' RNA duplex-unwinding activities of the hepatitis E virus helicase domain. | |
| | |
MedLine Citation:
|
PMID: 20071563 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
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. |
| | |
Authors:
|
Yogesh A Karpe; Kavita S Lole |
Related Documents
:
|
19605533 - A long-range rna-rna interaction between the 5' and 3' ends of the hcv genome. 11401543 - Rna-catalyzed amino acid activation. 1542643 - Functional complementation of internal deletion mutants in the lactose permease of esch... |
Publication Detail:
|
Type: Journal Article Date: 2010-01-13 |
Journal Detail:
|
Title: Journal of virology Volume: 84 ISSN: 1098-5514 ISO Abbreviation: J. Virol. Publication Date: 2010 Apr |
Date Detail:
|
Created Date: 2010-03-09 Completed Date: 2010-03-30 Revised Date: 2010-10-04 |
Medline Journal Info:
|
Nlm Unique ID: 0113724 Medline TA: J Virol Country: United States |
Other Details:
|
Languages: eng Pagination: 3595-602 Citation Subset: IM |
Affiliation:
|
Hepatitis Division, National Institute of Virology, Microbial Containment Complex, Sus Road, Pashan, Pune, India 411021, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adenosine Triphosphatases
/
metabolism Hepatitis E virus / enzymology* Nucleoside-Triphosphatase / chemistry, isolation & purification, metabolism* Protein Structure, Tertiary RNA Helicases / chemistry, isolation & purification, metabolism* RNA, Viral / chemistry* |
| Chemical | |
Reg. No./Substance:
|
0/RNA, Viral; EC 2.7.7.-/RNA Helicases; EC 3.6.1.-/Adenosine Triphosphatases; EC 3.6.1.15/Nucleoside-Triphosphatase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Glucose-dependent blood flow dynamics in murine pancreatic islets in vivo.
Next Document: Assessment Of Seasonal Influenza A Specific CD4 T Cell Responses To 2009 Pandemic H1N1 Swine-Origin ...