Dataset Information

POT1 proteins in green algae and land plants: DNA-binding properties and evidence of co-evolution with telomeric DNA.

ABSTRACT: Telomeric DNA terminates with a single-stranded 3' G-overhang that in vertebrates and fission yeast is bound by POT1 (Protection Of Telomeres). However, no in vitro telomeric DNA binding is associated with Arabidopsis POT1 paralogs. To further investigate POT1-DNA interaction in plants, we cloned POT1 genes from 11 plant species representing major branches of plant kingdom. Telomeric DNA binding was associated with POT1 proteins from the green alga Ostreococcus lucimarinus and two flowering plants, maize and Asparagus. Site-directed mutagenesis revealed that several residues critical for telomeric DNA recognition in vertebrates are functionally conserved in plant POT1 proteins. However, the plant proteins varied in their minimal DNA-binding sites and nucleotide recognition properties. Green alga POT1 exhibited a strong preference for the canonical plant telomere repeat sequence TTTAGGG with no detectable binding to hexanucleotide telomere repeat TTAGGG found in vertebrates and some plants, including Asparagus. In contrast, POT1 proteins from maize and Asparagus bound TTAGGG repeats with only slightly reduced affinity relative to the TTTAGGG sequence. We conclude that the nucleic acid binding site in plant POT1 proteins is evolving rapidly, and that the recent acquisition of TTAGGG telomere repeats in Asparagus appears to have co-evolved with changes in POT1 DNA sequence recognition.

SUBMITTER: Shakirov EV

PROVIDER: S-EPMC2794166 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

POT1 proteins in green algae and land plants: DNA-binding properties and evidence of co-evolution with telomeric DNA.

Shakirov Eugene V EV Song Xiangyu X Joseph Jessica A JA Shippen Dorothy E DE

Nucleic acids research 20091201 22

Telomeric DNA terminates with a single-stranded 3' G-overhang that in vertebrates and fission yeast is bound by POT1 (Protection Of Telomeres). However, no in vitro telomeric DNA binding is associated with Arabidopsis POT1 paralogs. To further investigate POT1-DNA interaction in plants, we cloned POT1 genes from 11 plant species representing major branches of plant kingdom. Telomeric DNA binding was associated with POT1 proteins from the green alga Ostreococcus lucimarinus and two flowering plan ...[more]

PMID: 19783822

Similar Datasets

Project description:BACKGROUND: The terrestrial habitat was colonized by the ancestors of modern land plants about 500 to 470 million years ago. Today it is widely accepted that land plants (embryophytes) evolved from streptophyte algae, also referred to as charophycean algae. The streptophyte algae are a paraphyletic group of green algae, ranging from unicellular flagellates to morphologically complex forms such as the stoneworts (Charales). For a better understanding of the evolution of land plants, it is of prime importance to identify the streptophyte algae that are the sister-group to the embryophytes. The Charales, the Coleochaetales or more recently the Zygnematales have been considered to be the sister group of the embryophytes However, despite many years of phylogenetic studies, this question has not been resolved and remains controversial. RESULTS: Here, we use a large data set of nuclear-encoded genes (129 proteins) from 40 green plant taxa (Viridiplantae) including 21 embryophytes and six streptophyte algae, representing all major streptophyte algal lineages, to investigate the phylogenetic relationships of streptophyte algae and embryophytes. Our phylogenetic analyses indicate that either the Zygnematales or a clade consisting of the Zygnematales and the Coleochaetales are the sister group to embryophytes. CONCLUSIONS: Our analyses support the notion that the Charales are not the closest living relatives of embryophytes. Instead, the Zygnematales or a clade consisting of Zygnematales and Coleochaetales are most likely the sister group of embryophytes. Although this result is in agreement with a previously published phylogenetic study of chloroplast genomes, additional data are needed to confirm this conclusion. A Zygnematales/embryophyte sister group relationship has important implications for early land plant evolution. If substantiated, it should allow us to address important questions regarding the primary adaptations of viridiplants during the conquest of land. Clearly, the biology of the Zygnematales will receive renewed interest in the future.

Dataset Information

POT1 proteins in green algae and land plants: DNA-binding properties and evidence of co-evolution with telomeric DNA.

Publications

POT1 proteins in green algae and land plants: DNA-binding properties and evidence of co-evolution with telomeric DNA.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets