What the papers say: Telomeric DNA binding proteins

The physical ends of eukaryotic chromosomes form a specialized nucleoprotein complex composed of DNA and DNA binding proteins. This nucleoprotein complex, termed the telomere, is essential for chromosome stability. In most organisms, the DNA portion of the nucleoprotein complex consists of simple tandem DNA repeats with one strand guanine rich. The protein portion of the complex is less well understood. The experiments presented in two recent papers^(1,2) represent different stages in the characterization of the telomeric DNA binding proteins. The first paper presents a structure-function study of the Oxytricha telomeric DNA binding proteins and the second paper shows the identification and initial characterization of a telomeric DNA binding activity from Xenopus laevis. These two reports provided valuable information in understanding the structure and function of telomeres.