Telomeric Repeat binding Factor or TTAGGG Repeat binding Factor, central (dimerization) domain Homology; TRFH. Telomeres are protein/DNA complexes that make up the physical ends of eukaryotic linear chromosomes and are essential for chromosome stability, protecting the chromosome ends from degradation and end-to-end fusion. Proteins TRF1, TRF2 and Taz1 bind telomeric DNA and are also involved in recruiting interacting proteins, TIN2, and Rap1, to the telomeres. It has also been demonstrated that PARP1 associates with TRF2 and is capable of poly(ADP-ribosyl)ation of TRF2, which affects binding of TRF2 to telomeric DNA. TRF1, TRF2 and Taz1 proteins contain three functional domains: an N-terminal acidic domain, a central TRF-specific/dimerization domain, and a C-terminal DNA binding domain with a single Myb-like repeat. Homodimerization, a prerequisite to DNA binding, results in the juxtaposition of two Myb DNA binding domains.