Linked Life Data

8810301

Source:http://linkedlifedata.com/resource/pubmed/id/8810301

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
1996-11-19
pubmed:abstractText
To address the functional significance of motif III in Escherichia coli DNA helicase II, the conserved aspartic acid at position 248 was changed to asparagine. UvrDD248N failed to form stable binary complexes with either DNA or ATP. However, UvrDD248N was capable of forming an active ternary complex when both ATP and single-stranded DNA were present. The DNA-stimulated ATPase activity of UvrDD248N was reduced relative to that of wild-type UvrD with no significant change in the apparent Km for ATP. The mutant protein also demonstrated a reduced DNA unwinding activity. The requirement for high concentrations of UvrDD248N to achieve unwinding of long duplex substrates likely reflects the reduced stability of various binary and ternary complexes that must exist in the catalytic cycle of a helicase. The data suggest that motif III may act as an interface between the ATP binding and DNA binding domains of a helicase. The uvrDD248N allele was also characterized in genetic assays. The D248N protein complemented the UV-sensitive phenotype of a uvrD deletion strain to levels nearly equivalent to wild-type helicase II. In contrast, the mutant protein only partially complemented the mutator phenotype. A correlation between the level of genetic complementation and the helicase activity of UvrDD248N is discussed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25360-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8810301-Adenosine Triphosphatases, pubmed-meshheading:8810301-Adenosine Triphosphate, pubmed-meshheading:8810301-Alleles, pubmed-meshheading:8810301-Amino Acid Sequence, pubmed-meshheading:8810301-Asparagine, pubmed-meshheading:8810301-Aspartic Acid, pubmed-meshheading:8810301-Binding Sites, pubmed-meshheading:8810301-DNA, pubmed-meshheading:8810301-DNA, Viral, pubmed-meshheading:8810301-DNA Helicases, pubmed-meshheading:8810301-Escherichia coli, pubmed-meshheading:8810301-Escherichia coli Proteins, pubmed-meshheading:8810301-Kinetics, pubmed-meshheading:8810301-Mutagenesis, Site-Directed, pubmed-meshheading:8810301-Peptide Fragments, pubmed-meshheading:8810301-Recombinant Proteins, pubmed-meshheading:8810301-Restriction Mapping, pubmed-meshheading:8810301-Ultraviolet Rays
pubmed:year
1996
pubmed:articleTitle
A partially functional DNA helicase II mutant defective in forming stable binary complexes with ATP and DNA. A role for helicase motif III.
pubmed:affiliation
Department of, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.