TAP-isolated KREPB4 and KREPB5 complexes retain precleaved editing activity. Editing activity on input RNA is only observed in the presence of guide RNA (+g), not in its absence (−g). Positive control activity (20S+) was obtained using a ∼20S fraction from gradient fractionated mitochondrial or whole-cell lysate. Asterisks in schematics denote location of radiolabel. Arrows indicate edited product. (A) Precleaved insertion assay of complexes isolated via KREPB4 wild type (WT), C51A/C54A, and E284A (left panel) or via KREPB5 wild type, C14A, E236A, V5-tagged wild type (WT-V5), F114S, and E122A (right panel). (B) Precleaved deletion cleavage assay of complexes described above.
