Cdc13 is an essential yeast protein required for telomere length regulation and genome stability. Cdc13, like a number of single-stranded telomere binding proteins, consists of several oligonucleotide-oligosaccharide binding (OB) folds. These folds potentially arise from evolutionary gene duplication and are involved in multiple functions, including nucleic acid and protein binding and Cdc13 dimerization. This entry represents the OB2 domain, second OB-fold counting from the N terminus of Cdc13. Biochemical assays indicate OB2 is not involved in telomeric DNA or Stn1 binding. However, disruption of the OB2 dimer in full-length Cdc13 affects Cdc13-Stn1 association, leading to telomere length deregulation, increased temperature sensitivity, and Stn1 binding defects. Hence it is suggested that the dimerization of the OB2 domain of Cdc13 is required for proper Cdc13, Stn1, Ten1 (CST) assembly and productive telomere capping [1].

1: Cdc13 OB2 dimerization required for productive Stn1 binding and efficient telomere maintenance. Mason M, Wanat JJ, Harper S, Schultz DC, Speicher DW, Johnson FB, Skordalakes E; Structure. 2013;21:109-120. PMID:23177925