Telomeric repeat-binding factor 1/2 (IPR017357)
Short name: TERF1/2
Overlapping homologous superfamilies
- Telomeric repeat-binding factor 1/2 (IPR017357)
- Telomeric repeat-binding factor 2 (IPR030657)
This group represents telomeric repeat-binding factors 1 (TERF1, also known as TRF1).
Telomeres function to shield chromosome ends from degradation and end-to-end fusions, as well as preventing the activation of DNA damage checkpoints. Telomeric repeat binding factor (TRF) proteins TRF1 and TRF2 are major components of vertebrate telomeres required for regulation of telomere stability. TRF1 and TRF2 bind to telomeric DNA as homodimers. Dimerisation involves the TRF homology (TRFH) subdomain contained within the dimerisation domain. The TRFH subdomain is important not only for dimerisation, but for DNA binding, telomere localisation, and interactions with other telomeric proteins. The dimerisation domains of TRF1 and TRF2 show the same multi-helical structure, arranged in a solenoid conformation similar to TPR repeats, which can be divided into an alpha-alpha superhelix and a long alpha hairpin [PMID: 11545737].
The two related human TRF proteins hTRF1 and hTRF2 form homodimers and bind directly to telomeric TTAGGG repeats via the myb DNA binding domain IPR001005 at the carboxy terminus [PMID: 15316005]. TRF1 is implicated in telomere length regulation and TRF2 in telomere protection [PMID: 15316005]. Other telomere complex associated proteins are recruited through their interaction with either TRF1 or TRF2. The fission yeast protein Taz1p (telomere-associated in Schizosaccharomyces pombe (Fission yeast) has similarity to both hTRF1 and hTRF2 and may perform the dual functions of TRF1 and TRF2 at fission yeast telomeres [PMID: 9034194].
- PIRSF038016 (Telomere_bd-1_Pin2)