An Ancient Clade of Penelope-Like Retroelements with Permuted Domains Is Present in the Green Lineage and Protists, and Dominates Many Invertebrate Genomes.

ABSTRACT: Penelope-like elements (PLEs) are an enigmatic clade of retrotransposons whose reverse transcriptases (RTs) share a most recent common ancestor with telomerase RTs. The single ORF of canonical endonuclease (EN)+ PLEs encodes RT and a C-terminal GIY-YIG EN that enables intrachromosomal integration, whereas EN- PLEs lack EN and are generally restricted to chromosome termini. EN+ PLEs have only been found in animals, except for one case of horizontal transfer to conifers, whereas EN- PLEs occur in several kingdoms. Here, we report a new, deep-branching PLE clade with a permuted domain order, whereby an N-terminal GIY-YIG EN is linked to a C-terminal RT by a short domain with a characteristic CxC motif. These N-terminal EN+ PLEs share a structural organization, including pseudo-LTRs and comple

SUBMITTER: Craig RJ 

PROVIDER: S-EPMC8557442 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature