Linked Life Data

10212190

Source:http://linkedlifedata.com/resource/pubmed/id/10212190

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1999-6-3
pubmed:abstractText
Eukaryotic initiation factor (eIF) 4A is the prototypic member of the DEAD box family of proteins and has been proposed to act as an RNA helicase to unwind secondary structure in the 5'-untranslated region of eukaryotic mRNAs. Previous studies have shown that the RNA helicase activity of eIF4A is dependent on the presence of a second initiation factor, eIF4B. In this report, eIF4A has been demonstrated to function independently of eIF4B as an ATP-dependent RNA helicase. The biochemical and kinetic properties of this activity were examined. By using a family of RNA duplexes with an unstructured single-stranded region followed by a duplex region of increasing length and stability, it was observed that the initial rate of duplex unwinding decreased with increasing stability of the duplex. Furthermore, the maximum amount of duplex unwound also decreased with increasing stability. Results suggest that eIF4A acts in a non-processive manner. eIF4B and eIF4H were shown to stimulate the helicase activity of eIF4A, allowing eIF4A to unwind longer, more stable duplexes with both an increase in initial rate and maximum amount of duplex unwound. A simple kinetic model is proposed to explain the mechanism by which eIF4A unwinds RNA duplex structures in an ATP-dependent manner.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12236-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Biochemical and kinetic characterization of the RNA helicase activity of eukaryotic initiation factor 4A.
pubmed:affiliation
Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4935, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.