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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
48
pubmed:dateCreated
2004-11-23
pubmed:abstractText
We have recently published the crystal structure of the adeno-associated virus type 2 superfamily 3 (SF3) helicase Rep40. Although based on its biochemical properties it is unlikely that Rep40 plays a central role as a replicative helicase the involvement of this motor protein in DNA packaging has recently been demonstrated. Here we focused our attention on residues that fall within and adjacent to the B' motif of SF3 helicases that directly interact with single-stranded DNA during translocation of the motor protein. In vitro, alanine substitution at positions Lys-404 or Lys-406 abrogated the ability of the protein to interact with single-stranded DNA as demonstrated by electrophoretic mobility shift assay and fluorescence anisotropy, and accordingly these mutants could not unwind a partially duplex DNA substrate. Despite this loss of helicase activity, basal ATPase activity in these mutants remained intact. However, unlike the wild-type protein, K404A and K406A ATPase activity was not stimulated by DNA. As predicted, disruption of motor activity through interference with DNA binding resulted in an inability of Rep40 to package adeno-associated virus DNA in a tissue culture-based assay. Taken together, we characterized, for the first time in an SF3 helicase family member, residues that are directly involved in single-stranded DNA binding and that are critical for the Rep motor activity. Based on our findings we propose B' as the signature motif of SF3 helicases that is responsible for the complex interactions required for the coupling of DNA binding and ATP hydrolysis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
50472-81
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Residues within the B' motif are critical for DNA binding by the superfamily 3 helicase Rep40 of adeno-associated virus type 2.
pubmed:affiliation
Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't