C-terminal domain of RAP1 recruits proteins to telomeres
The RAP1 (repressor activator protein 1) C-terminal domain (RCT) mediates interactions with other proteins such as TRF2 (human), Rif1, Rif2, Sir3, Sir4 (Saccharomyces cerevisiae), and Taz1 (Schizosaccharomyces pombe) at telomeres and other loci. RAP1, identified in budding yeast as repressor/activator protein 1, is a well-conserved telomere binding protein, also found in fission yeast and mammals. In Saccharomyces cerevisiae, RAP1 directly binds DNA and is involved in transcriptional activation, gene silencing, as well as binding at numerous sites at each telemore, where it functions in telomere length regulation, telomeric position effect gene silencing and telomere end protection. Human RAP1 apparently does not bind telomeric DNA directly, but binds telomere repeat binding factor 2 (TRF2) via the RCT. RAP1 might act by suppressing nonhomologous end-joining. Yeast RAP1 has two myb-type DNA binding modules, and an RCT domain that recruits Sir proteins 3 and 4 (Sir3, Sir4) for gene silencing, and Rif1 and Rif2 for telomere length maintenance. Schizosaccharomyces pombe RAP1 (spRap1), like human RAP1, lacks direct DNA-binding activity and is localized to telomeres via Taz1, an ortholog of TRF1 and TRF2. The S. pompe RCT resembles the first 3-helix bundle of the yeast and human RCT forms, but is not included in this larger model.
Feature 1:recruitment target interaction site [polypeptide binding site]
Evidence:
Comment:RAP1 recruits proteins, for example, TRF2 (human), Rif1, Rif2, Sir3, Sir4 (S. cerevisiae), and Taz1 (S. pombe) to telomeres and other loci via the RCT.
Structure:3K6G: Human RAP1 binds TRF2, contacts at 4.0A
Structure:3OWT: Saccharomyces cerevisiae RAP1 binds Sir3, contacts at 4.0A
Jiyao W et al.(2023). "The conserved domain database in 2023.",