Structural basis of human telomerase recruitment by TPP1-POT1.

Publication Year
2022

Type

Journal Article
Abstract

Telomerase maintains genome stability by extending the 3' telomeric repeats at eukaryotic chromosome ends, thereby counterbalancing progressive loss caused by incomplete genome replication. In mammals, telomerase recruitment to telomeres is mediated by TPP1, which assembles as a heterodimer with POT1. We report structures of DNA-bound telomerase in complex with TPP1 and with TPP1-POT1 at 3.2- and 3.9-angstrom resolution, respectively. Our structures define interactions between telomerase and TPP1-POT1 that are crucial for telomerase recruitment to telomeres. The presence of TPP1-POT1 stabilizes the DNA, revealing an unexpected path by which DNA exits the telomerase active site and a DNA anchor site on telomerase that is important for telomerase processivity. Our findings rationalize extensive prior genetic and biochemical findings and provide a framework for future mechanistic work on telomerase regulation.

Journal
Science (New York, N.Y.)
Volume
375
Issue
6585
Pages
1173-1176
Date Published
03/2022
ISSN Number
1095-9203
Alternate Journal
Science
PMCID
PMC7612489
PMID
35201900