Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity

Casposons are a superfamily of putative self-synthesizing transposable elements that are predicted to employ a homolog of Cas1 protein as a recombinase and could have contributed to the origin of the CRISPR-Cas adaptive immunity systems in archaea and bacteria. Casposons remain uncharacterized exper...

Full description

Bibliographic Details
Main Authors:	Krupovic, Mart, Shmakov, Sergey, Makarova, Kira S., Forterre, Patrick, Koonin, Eugene V.
Format:	Online
Language:	English
Published:	Oxford University Press 2016
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4779613/

id	pubmed-4779613
recordtype	oai_dc
spelling	pubmed-47796132016-03-07 Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity Krupovic, Mart Shmakov, Sergey Makarova, Kira S. Forterre, Patrick Koonin, Eugene V. Research Article Casposons are a superfamily of putative self-synthesizing transposable elements that are predicted to employ a homolog of Cas1 protein as a recombinase and could have contributed to the origin of the CRISPR-Cas adaptive immunity systems in archaea and bacteria. Casposons remain uncharacterized experimentally, except for the recent demonstration of the integrase activity of the Cas1 homolog, and given their relative rarity in archaea and bacteria, original comparative genomic analysis has not provided direct indications of their mobility. Here, we report evidence of casposon mobility obtained by comparison of the genomes of 62 strains of the archaeon Methanosarcina mazei. In these genomes, casposons are variably inserted in three distinct sites indicative of multiple, recent gains, and losses. Some casposons are inserted into other mobile genetic elements that might provide vehicles for horizontal transfer of the casposons. Additionally, many M. mazei genomes contain previously undetected solo terminal inverted repeats that apparently are derived from casposons and could resemble intermediates in CRISPR evolution. We further demonstrate the sequence specificity of casposon insertion and note clear parallels with the adaptation mechanism of CRISPR-Cas. Finally, besides identifying additional representatives in each of the three originally defined families, we describe a new, fourth, family of casposons. Oxford University Press 2016-01-11 /pmc/articles/PMC4779613/ /pubmed/26764427 http://dx.doi.org/10.1093/gbe/evw006 Text en © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. http://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Krupovic, Mart Shmakov, Sergey Makarova, Kira S. Forterre, Patrick Koonin, Eugene V.
spellingShingle	Krupovic, Mart Shmakov, Sergey Makarova, Kira S. Forterre, Patrick Koonin, Eugene V. Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity
author_facet	Krupovic, Mart Shmakov, Sergey Makarova, Kira S. Forterre, Patrick Koonin, Eugene V.
author_sort	Krupovic, Mart
title	Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity
title_short	Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity
title_full	Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity
title_fullStr	Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity
title_full_unstemmed	Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity
title_sort	recent mobility of casposons, self-synthesizing transposons at the origin of the crispr-cas immunity
description	Casposons are a superfamily of putative self-synthesizing transposable elements that are predicted to employ a homolog of Cas1 protein as a recombinase and could have contributed to the origin of the CRISPR-Cas adaptive immunity systems in archaea and bacteria. Casposons remain uncharacterized experimentally, except for the recent demonstration of the integrase activity of the Cas1 homolog, and given their relative rarity in archaea and bacteria, original comparative genomic analysis has not provided direct indications of their mobility. Here, we report evidence of casposon mobility obtained by comparison of the genomes of 62 strains of the archaeon Methanosarcina mazei. In these genomes, casposons are variably inserted in three distinct sites indicative of multiple, recent gains, and losses. Some casposons are inserted into other mobile genetic elements that might provide vehicles for horizontal transfer of the casposons. Additionally, many M. mazei genomes contain previously undetected solo terminal inverted repeats that apparently are derived from casposons and could resemble intermediates in CRISPR evolution. We further demonstrate the sequence specificity of casposon insertion and note clear parallels with the adaptation mechanism of CRISPR-Cas. Finally, besides identifying additional representatives in each of the three originally defined families, we describe a new, fourth, family of casposons.
publisher	Oxford University Press
publishDate	2016
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4779613/
_version_	1613547977439182848

Recent Mobility of Casposons, Self-Synthesizing Transposons at the Origin of the CRISPR-Cas Immunity

Similar Items