Chapter category:

Telomerase: Evolution, Structure and Function

This chapter appears in the following book:

Origin and Evolution of Telomeres

Edited by: Jozef Nosek and Ľubomír Tomáska
ISBN: 978-1-58706-309-1
» Get more information about this book at landesbioscience.com «

Chapter authors:
Marie-Eve Brault, Yasmin D'Souza and Chantal Autexier

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Telomerase is a unique ribonucleoprotein reverse transcriptase that uses an integral RNA template to catalyze the addition of telomeric repeats at telomeres. This mechanism is required for the maintenance of chromosome termini, as the structure and integrity of telomeres are essential for genome stability. Although the catalytic subunit of the enzyme shares several features with other reverse transcriptases, it differs in having telomerase-specific structures and functions. Structurally, the telomerase reverse transcriptase protein component contains unique amino–and carboxy–terminal domains that flank centrally-located reverse transcriptase motifs. Functionally, unlike reverse transcriptases, telomerase contains an integral RNA component and is able to synthesize telomeric repeats. Here we discuss the evolutionary relationship of telomerase to other nucleic acid polymerases and reverse transcriptases and the various functions that regulate the elongation of chromosome ends. Such functions include interaction with the DNA substrate, nucleolytic activity, multimerization and processivity. In addition, we propose telomere‑lengthening independent functions ascribed to telomerase.

Marie-Eve Brault
Departments of Anatomy and Cell Biology, McGill University, Bloomfield Centre for Research in Aging, Sir Mortimer B. Davis Jewish General Hospital

Yasmin D'Souza
Departments of Anatomy and Cell Biology, McGill University, Bloomfield Centre for Research in Aging, Sir Mortimer B. Davis Jewish General Hospital

Chantal Autexier
Departments of Anatomy, Medicene and Cell Biology, McGill University, Bloomfield Centre for Research in Aging, Sir Mortimer B. Davis Jewish General Hospital

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Chapter category:

Telomerase: Evolution, Structure and Function

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