Binding linkage in a telomere DNA-protein complex at the ends of Oxytricha nova chromosomes.

ABSTRACT: Alpha and beta protein subunits of the telomere end binding protein from Oxytricha nova (OnTEBP) combine with telomere single strand DNA to form a protective cap at the ends of chromosomes. We tested how protein-protein interactions seen in the co-crystal structure relate to DNA binding through use of fusion proteins engineered as different combinations of domains and subunits derived from OnTEBP. Joining alpha and beta resulted in a protein that bound single strand telomere DNA with high affinity (K(D-DNA)=1.4 nM). Another fusion protein, constructed without the C-terminal protein-protein interaction domain of alpha, bound DNA with 200-fold diminished affinity (K(D-DNA)=290 nM) even though the DNA-binding domains of alpha and beta were joined through a peptide linker. Adding back the alph

SUBMITTER: Buczek P 

PROVIDER: S-EPMC2939017 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature