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The yeast telomere‐binding protein RAP1 binds to and promotes the formation of DNA quadruplexes in telomeric DNA.
Author(s) -
Giraldo R.,
Rhodes D.
Publication year - 1994
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1994.tb06526.x
Subject(s) - biology , telomere , telomere binding protein , dna , g quadruplex , genetics , dna binding protein , hmg box , rap1 , yeast , microbiology and biotechnology , gene , transcription factor
The protein RAP1 is essential for the maintenance of the telomeres of Saccharomyces cerevisiae and binds in vitro to multiple sites found within the TG1‐3 telomeric repeats. We show here that, in addition to its known binding activity for double‐stranded DNA, RAP1 binds sequence‐specifically to the GT‐strands. This indicates that RAP1 is the protein that binds to the telomeric terminal GT‐tails. Furthermore, we have found that RAP1 binds to and promotes the formation of G‐tetrads, i.e. DNA quadruplexes, in GT‐strand oligonucleotides at nanomolar concentrations. The formation of DNA quadruplexes appears to involve the intermolecular association of GT‐strands. The minimal DNA‐binding domain of RAP1 (DBD) binds only to double‐stranded DNA, so that the novel DNA‐binding activity we have found involves regions of the protein located outside of the DBD. The finding that a telomeric protein promotes the formation of G‐tetrads argues for the use of DNA quadruplexes in telomere association.