Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
2007-8-29
pubmed:abstractText
RNA helicases regulate virtually all RNA-dependent cellular processes. Although much is known about helicase structures, very little is known about how they deal with barriers in RNA and the factors that affect their processivity. The hepatitis C virus encodes NS3, an RNA helicase that is essential for viral RNA replication. We have used optical tweezers to determine at the single-molecule level how the local stability of the RNA substrate affects the enzyme rate of strand separation, whether separation occurs by an active or a passive mechanism, and whether processivity is affected. We show that sequence barriers in RNA modulate NS3 activity. NS3 processivity depends on barriers ahead of the opening fork. Our results rule out a model where NS3 passively waits for the thermal fraying of double-stranded RNA. Instead, we find that NS3 destabilizes the duplex before separating the strands. Failure to do so before a strong barrier leads to helicase dissociation and limits the processivity of the enzyme.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-10667799, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-11139627, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-11207360, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-11326101, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-11467951, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-12206763, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-12624910, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-12649482, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-12947199, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-1439819, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-14991003, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-15269774, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-15381423, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-15561144, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-15652481, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-15806107, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-16397502, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-16569413, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-16606839, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-17499041, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-8079175, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-8392863, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-8811178, http://linkedlifedata.com/resource/pubmed/commentcorrection/17709749-9671724
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
104
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13954-9
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
NS3 helicase actively separates RNA strands and senses sequence barriers ahead of the opening fork.
pubmed:affiliation
QB3 Institute, University of California, Berkeley, CA 94720, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural