Evidence for a HeLa nuclear protein that binds specifically to the single-stranded d(CCCTAA)n telomeric motif.
In recent years several telomere binding proteins from eukaryotic organisms have been identified that are able to recognise specifically the duplex telomeric DNA repeat or the G-rich 3'-ending single strand. In this paper we present experimental evidence that HeLa nuclear extracts contain a protein that binds with high specificity to the single-stranded complementary d(CCCTAA)n repeat. Electrophoretic mobility shift assays show that the oligonucleotide d(CCCTAACCCTAACCCTAACCCT) forms a stable complex with this protein in the presence of up to 1000-fold excesses of single-stranded DNA and RNA competitors, but is prevented from doing so in the presence of its complementary strand. SDS-PAGE experiments after UV cross-linking of the complex provide an estimate of 50 kDa for the molecular weight of this protein.
Marsich
E
E
Department of Biochemistry, Biophysics and Macromolecular Chemistry, University of Trieste, Italy.
Piccini
A
A
Xodo
L E
LE
Manzini
G
G
D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D014466:Ultraviolet Rays
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides