7LMA

Tetrahymena telomerase T3D2 structure at 3.3 Angstrom

Summary for 7LMA

• Entry DOI: 10.2210/pdb7lma/pdb
• EMDB information: 23437 23438
• Descriptor: Telomerase La-related protein p65, Telomerase reverse transcriptase, Telomerase holoenzyme Teb1 subunit, ... (9 entities in total)
• Functional Keywords: telomerase, polymerase, reverse transcriptase, ribonucleoprotein, replication, replication-rna-dna complex, replication/rna/dna
• Biological source: Tetrahymena thermophila; More
• Total number of polymer chains: 8
• Total formula weight: 435178.42

Authors

He, Y.,Wang, Y.,Liu, B.,Helmling, C.,Susac, L.,Cheng, R.,Zhou, Z.H.,Feigon, J. (deposition date: 2021-02-05, release date: 2021-05-12, Last modification date: 2024-03-06)

Primary citation

He, Y.,Wang, Y.,Liu, B.,Helmling, C.,Susac, L.,Cheng, R.,Zhou, Z.H.,Feigon, J.
Structures of telomerase at several steps of telomere repeat synthesis.
Nature, 593:454-459, 2021

PubMed Abstract: Telomerase is unique among the reverse transcriptases in containing a noncoding RNA (known as telomerase RNA (TER)) that includes a short template that is used for the processive synthesis of G-rich telomeric DNA repeats at the 3' ends of most eukaryotic chromosomes. Telomerase maintains genomic integrity, and its activity or dysregulation are critical determinants of human longevity, stem cell renewal and cancer progression. Previous cryo-electron microscopy structures have established the general architecture, protein components and stoichiometries of Tetrahymena and human telomerase, but our understandings of the details of DNA-protein and RNA-protein interactions and of the mechanisms and recruitment involved remain limited. Here we report cryo-electron microscopy structures of active Tetrahymena telomerase with telomeric DNA at different steps of nucleotide addition. Interactions between telomerase reverse transcriptase (TERT), TER and DNA reveal the structural basis of the determination of the 5' and 3' template boundaries, handling of the template-DNA duplex and separation of the product strand during nucleotide addition. The structure and binding interface between TERT and telomerase protein p50 (a homologue of human TPP1) define conserved interactions that are required for telomerase activation and recruitment to telomeres. Telomerase La-related protein p65 remodels several regions of TER, bridging the 5' and 3' ends and the conserved pseudoknot to facilitate assembly of the TERT-TER catalytic core.

PubMed: 33981033
DOI: 10.1038/s41586-021-03529-9

Experimental method

ELECTRON MICROSCOPY (3.3 Å)