Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-2-9
pubmed:abstractText
The Ku autoantigen is a heterodimer of 70 (p70) and approximately 80 kDa (p80) subunits that is the DNA-binding component of the DNA-dependent protein kinase (DNA-PK) complex involved in DNA repair and V(D)J recombination. Binding to DNA ends is critical to the function of DNA-PK, but how Ku interacts with DNA is not completely understood. To define the role of p70 and p80 and their dimerization in DNA binding, heterodimers were assembled by co-expressing the subunits using recombinant baculoviruses. Two p70 dimerization sites, amino acids 1-115 and 430-482, respectively, were identified. Binding of p70 to linear double-stranded DNA could be demonstrated by an immunoprecipitation assay, and required the C-terminal portion (amino acids 430-609), but not interaction with p80. The p70 mutants 1-600, 1-542, 1-115, and 430-600 did not bind DNA efficiently. However, DNA binding of 1-600, 1-542, and 1-115, but not 430-600, was restored by dimerization with p80, indicating that p70 has two DNA binding sites, each partially overlapping one of the dimerization sites. The C-terminal domain can bind DNA by itself, but the N-terminal domain requires dimerization with p80. These observations could be relevant to the multiple functional activities of Ku and explain controversies regarding the role of dimerization in DNA binding.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
842-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Identification of two domains of the p70 Ku protein mediating dimerization with p80 and DNA binding.
pubmed:affiliation
Department of Medicine, Thurston Arthritis Research Center, UNC Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7280, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't