Telomere G-strand structure and function analyzed by chemical protection, base analog substitution, and utilization by telomerase in vitro

Supplemental Files
Date
1990
Authors
Henderson, Eric
Moore, Michael
Malcolm, Bruce
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Zoology and Genetics
Organizational Unit
Journal Issue
Series
Abstract

Eukaryotic telomeres have a 12-1 6 nucleotide long deoxyguanosine (dG) rich single-stranded overhang at their molecular termini. Some of the unique features of telomeres are probably attributable to a specialized structure formed by this overhang. In the ciliated protozoan Tetrahymena thermophila, the dG-rich overhang is comprised of approximately two repeats of the sequence d(TTGGGG). Previous work has shown that the synthetic oligonucleotide d(TTGGGG),, can form an unusual non-Watson-Crick base-paired structure (the "G-strand structure") containing G-G base pairs and syn-guanines. We have tested the susceptibility of various dGs in this structure to methylation by DMS. At 0-10 "C one dG residue is hypersensitive to methylation while others are particularly resistant. By systematically substituting deoxyinosine (dI) for dG in d(TTGGGG)4 we identify N2 groups of guanine essential for formation of the G-strand structure. We show that dI-substituted molecules that cannot form the G-strand structure nonetheless function as substrates for telomere repeat addition in vitro by the telomere lengthening enzyme, telomerase. The implications of these data are discussed.

Description

Reprinted (adapted) with permission from Telomere G-strand structure and function analyzed by chemical protection, base analog substitution, and utilization by telomerase in vitro. Eric R. Henderson, Michael Moore, and Bruce A. Malcolm. Biochemistry 1990 29 (3), 732-737. DOI: 10.1021/bi00455a020. Copyright 1990 American Chemical Society.

Keywords
Citation
DOI
Collections