Fission Yeast Telomeric DNA Binding Protein Pot1 Has The Ability To Unfold Tetraplex Structure of Telomeric DNA

Abstract

To understand the regulation mechanism of fission yeast telomeric DNA, we analyzed the structural properties of 4Gn: d(G_nTTAC)₄ (n = 3, 4) and their interaction with the single-stranded telomeric DNA binding domain of telomere-binding protein Pot1 (Pot1DBD). 4G4 adopted only an antiparallel tetraplex in spite of a mixture of parallel and antiparallel tetraplexes of 4G3. The antiparallel tetraplex of 4G4 became unfolded upon the interaction with Pot1DBD. Considering that the antiparallel tetraplex inhibits telomerase-mediated telomere elongation, we conclude that the ability of Pot1 to unfold the antiparallel tetraplex is required for telomerase-mediated telomere regulation.

Keywords:

• Fission yeast telomeric DNA
• antiparallel triplex
• structure
• unfolding

I would like to thank Ms. Ayako Furukawa for her technical assistance. This research was supported in part by Grants-in-Aid for Scientific Research (B) (16390083) and Priority Areas (17012022 and 17053027) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.