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

ABSTRACT: R2 retrotransposons are site-specific eukaryotic non-long terminal repeat 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 well characterized. Here, we report high-resolution cryo-electron microscopy structures of two vertebrate A-clade R2 proteins at the initiation of target-primed reverse transcription and after cDNA synthesis and second-strand nicking. Using biochemical and cellular assays, we illuminate the basis for high selectivity of template use and unique roles for each of the three zinc-finger domains in nucleic acid recog

SUBMITTER: Thawani A 

PROVIDER: S-EPMC12180492 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature