Structures of vertebrate R2 retrotransposon complexes during target-primed reverse transcription and after second strand nicking.

ABSTRACT: R2 retrotransposons are model site-specific eukaryotic non-LTR retrotransposons that copy-and-paste into gene loci encoding ribosomal RNAs. Recently we demonstrated that avian A-clade R2 proteins achieve efficient and precise insertion of transgenes into their native safe-harbor loci in human cells. The features of A-clade R2 proteins that support gene insertion are not characterized. Here, we report high resolution cryo-electron microscopy structures of two vertebrate A-clade R2 proteins, avian and testudine, at the initiation of target-primed reverse transcription and one structure after cDNA synthesis and second strand nicking. Using biochemical and cellular assays we discover the basis for high selectivity of template use and unique roles for each of the expanded A-clade zinc-finger do

SUBMITTER: Thawani A 

PROVIDER: S-EPMC11601368 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature