Structural basis for the evolution of a domesticated group II intron-like reverse transcriptase to function in host cell DNA repair.

ABSTRACT: A previous study found that a bacterial group II intron-like reverse transcriptase (G2L4 RT) evolved to function in double-strand break repair (DSBR) via microhomology-mediated end-joining (MMEJ) and that a mobile group II intron-encoded RT has a basal DSBR activity that uses conserved structural features of non-long terminal repeat (non-LTR)-retroelement RTs. Here, we determined G2L4 RT apoenzyme and snap-back DNA synthesis structures revealing unique structural adaptations that optimized its cellular function in DSBR. These included an RT3a structure that stabilizes the apoenzyme in an inactive conformation until encountering a DNA substrate; a longer N-terminal extension/RT0-loop with conserved residues that together with a modified active site favors strand annealing; and a conserved d

SUBMITTER: Park SK 

PROVIDER: S-EPMC12337344 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature