冷冻电镜揭示出芽酵母端粒酶全酶结构

Full article and list of author affiliations: https://doi.org/10.1126/ science.adz5344 Hongmiao Hu*, Hannah Neumann, Gabriela M. Teplitz, Elsa Franco-Echevarría, Pascal Chartrand*, Raymund J. Wellinger*, Thi Hoang Duong Nguyen* INTRODUCTION: Telomerase adds telomeric DNA repeats to chromosome ends, preserving genome integrity. Its catalytic core comprises telomerase reverse transcriptase (TERT) that synthesizes DNA using an RNA template within telomerase RNA (TR). Across eukaryotes, TRs vary greatly in sizes and predicted secondary structures, resulting in a substantial diversity in holoenzyme composition. Studies in ciliates, yeasts, and humans have been pivotal in establishing our understanding of telomerase biology. Cryo–electron microscopy (cryo-EM) structures of human and Tetrahymena telomerases have provided insights into their architecture, mechanism, and regulation. Structures of active yeast telomerase remain lacking. …