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Promotion of parallel DNA quadruplexes by a yeast telomere binding protein: a circular dichroism study.

1994; National Academy of Sciences; Volume: 91; Issue: 16 Linguagem: Inglês

10.1073/pnas.91.16.7658

1091-6490

Rafael Giraldo, Masashi Suzuki, Colin A. Chapman, Daniela Rhodes,

RNA and protein synthesis mechanisms

Repressor-activator protein 1 (RAP1) has an essential role in the maintenance of yeast telomeres. Yeast telomeric DNA consists of simple repeated G-rich sequences that are bound by RAP1. We have found that RAP1, in addition to its known binding activity for double-stranded DNA, interacts with the G-rich strand containing guanine base (G)-tetrads. We show here using circular dichroism spectroscopy that RAP1 promotes the formation of one particular type of DNA quadruplex, parallel G4-DNA. Furthermore, RAP1 is able to bind to both preformed parallel and antiparallel DNA quadruplexes. These results have implications for the possible use of DNA quadruplexes in telomere-telomere association in vivo.