6ZDP image
Entry Detail
PDB ID:
6ZDP
Keywords:
Title:
Structure of telomerase from Candida Tropicalis in complexe with TWJ fragment of telomeric RNA
Biological Source:
PDB Version:
Deposition Date:
2020-06-15
Release Date:
2021-04-28
Method Details:
Experimental Method:
Resolution:
2.85 Å
R-Value Free:
0.27
R-Value Work:
0.21
R-Value Observed:
0.22
Space Group:
C 2 2 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Telomerase reverse transcriptase
Chain IDs:A
Chain Length:724
Number of Molecules:1
Biological Source:Candida tropicalis (strain ATCC MYA-3404 / T1)
Polymer Type:polyribonucleotide
Description:Chains: B
Chain IDs:B
Chain Length:72
Number of Molecules:1
Biological Source:Candida tropicalis MYA-3404
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
MSE A MET modified residue
Primary Citation
Crystal structures of N-terminally truncated telomerase reverse transcriptase from fungi‡.
Nucleic Acids Res. 49 4768 4781 (2021)
PMID: 33856462 DOI: 10.1093/nar/gkab261

Abstact

Telomerase plays critical roles in cellular aging, in the emergence and/or development of cancer, and in the capacity for stem-cell renewal, consists of a catalytic telomerase reverse transcriptase (TERT) and a template-encoding RNA (TER). TERs from diverse organisms contain two conserved structural elements: the template-pseudoknot (T-PK) and a helical three-way junction (TWJ). Species-specific features of the structure and function of telomerase make obtaining a more in-depth understanding of the molecular mechanism of telomerase particularly important. Here, we report the first structural studies of N-terminally truncated TERTs from Candida albicans and Candida tropicalis in apo form and complexed with their respective TWJs in several conformations. We found that Candida TERT proteins perform only one round of telomere addition in the presence or absence of PK/TWJ and display standard reverse transcriptase activity. The C-terminal domain adopts at least two extreme conformations and undergoes conformational interconversion, which regulates the catalytic activity. Most importantly, we identified a conserved tertiary structural motif, called the U-motif, which interacts with the reverse transcriptase domain and is crucial for catalytic activity. Together these results shed new light on the structure and mechanics of fungal TERTs, which show common TERT characteristics, but also display species-specific features.

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