Single-Base Pair Unwinding and Asynchronous RNA Release by the Hepatitis C Virus NS3 Helicase.
Summary of "Single-Base Pair Unwinding and Asynchronous RNA Release by the Hepatitis C Virus NS3 Helicase."
Nonhexameric helicases use adenosine triphosphate (ATP) to unzip base pairs in double-stranded nucleic acids (dsNAs). Studies have suggested that these helicases unzip dsNAs in single-base pair increments, consuming one ATP molecule per base pair, but direct evidence for this mechanism is lacking. We used optical tweezers to follow the unwinding of double-stranded RNA by the hepatitis C virus NS3 helicase. Single-base pair steps by NS3 were observed, along with nascent nucleotide release that was asynchronous with base pair opening. Asynchronous release of nascent nucleotides rationalizes various observations of its dsNA unwinding and may be used to coordinate the translocation speed of NS3 along the RNA during viral replication.
Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA.
This article was published in the following journal.
Name: Science (New York, N.Y.)
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21940894
- DOI: http://dx.doi.org/10.1126/science.1206023
Medical and Biotech [MESH] Definitions
A family of hepatotropic DNA viruses which contains double-stranded DNA genomes and causes hepatitis in humans and animals. There are two genera: AVIHEPADNAVIRUS and ORTHOHEPADNAVIRUS. Hepadnaviruses include HEPATITIS B VIRUS, duck hepatitis B virus (HEPATITIS B VIRUS, DUCK), heron hepatitis B virus, ground squirrel hepatitis virus, and woodchuck hepatitis B virus (HEPATITIS B VIRUS, WOODCHUCK).
INFLAMMATION of the LIVER in humans caused by HEPATITIS C VIRUS, a single-stranded RNA virus. Its incubation period is 30-90 days. Hepatitis C is transmitted primarily by contaminated blood parenterally, and is often associated with transfusion and intravenous drug abuse. However, in a significant number of cases, the source of hepatitis C infection is unknown.
Acute INFLAMMATION of the LIVER in humans; caused by HEPATITIS E VIRUS, a non-enveloped single-stranded RNA virus. Similar to HEPATITIS A, its incubation period is 15-60 days and is enterically transmitted, usually by fecal-oral transmission.
Hepatitis A Virus
A species in the genus HEPATOVIRUS containing one serotype and two strains: HUMAN HEPATITIS A VIRUS and Simian hepatitis A virus causing hepatitis in humans (HEPATITIS A) and primates, respectively.
An unassigned genus of RNA viruses with a single officially described species, HEPATITIS E VIRUS. A distantly related virus, Avian hepatitis E virus, has been listed as a tentative species. Strains have also been identified in swine. The family name hepeviridae has been proposed.
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