DNA-induced dimerization of the single-stranded DNA binding telomeric protein Pot1 from Schizosaccharomyces pombe.

ABSTRACT: Eukaryotic chromosome ends are protected from illicit DNA joining by protein-DNA complexes called telomeres. In most studied organisms, telomeric DNA is composed of multiple short G-rich repeats that end in a single-stranded tail that is protected by the protein POT1. Mammalian POT1 binds two telomeric repeats as a monomer in a sequence-specific manner, and discriminates against RNA of telomeric sequence. While addressing the RNA discrimination properties of SpPot1, the POT1 homolog in Schizosaccharomyces pombe, we found an unanticipated ssDNA-binding mode in which two SpPot1 molecules bind an oligonucleotide containing two telomeric repeats. DNA binding seems to be achieved via binding of the most N-terminal OB domain of each monomer to each telomeric repeat. The SpPot1 dimer may have evo

SUBMITTER: Nandakumar J 

PROVIDER: S-EPMC3245936 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature