A specialized SUV3 RNA helicase is involved in plant mitochondrial DNA repair

Mutations in the mitochondrially targeted RNA helicase AtSUV3 in Arabidopsis thaliana increase ectopic mitochondrial recombination and hypersensitivity to ciprofloxacin-induced mitochondrial DNA damage.

• Why it matters: Land plant mitochondrial genomes show low coding substitution rates but high non-coding rearrangements, implying DNA damage and repair must be reconciled with strong coding sequence preservation.
• What they did: The study characterized AtSUV3 (At4g14790) using ciprofloxacin sensitivity assays, CRISPR knockout lines, and recombinant AtSUV3 showing ATP-dependent RNA helicase activity with preference for 3'-ended substrates.
• The result: The results identify AtSUV3 as a factor involved in mitochondrial double-strand DNA break repair and suggest a specialized role distinct from the SUV3-like paralog AT5G39840.1.