Fig. 1

Molecular characterization of two novel PPO3 mutations. a Schematic representation of the PPO3 gene locus and PPO3 coding sequence. The gene map was adapted from FlyBase. The PPO3 ¹ mutation was present in the PPO1 ^Δ ,2 ^Δ double-mutant stock while the PPO3 ^SK3 mutation was generated by CRISPR/Cas9. Shown are the protein domains of PPO3 and a partial sequence where the deleted nucleotides are marked in red. b Structural modeling shows that the PPO3 ¹ mutation (orange portion) deletes most of the catalytic pocket, including copper-coordinating residues of the copper-binding domain A (light blue). Protein domains are colored as in (a). c Lifespan analysis of unchallenged flies reveals an increase in mortality rate of PPO1 ^Δ ,2 ^Δ and PPO1 ^Δ ,2 ^Δ ,3 ¹ mutant flies but not PPO3 ¹ mutants. Each survival curve corresponds to three independent experiments with 20 flies each. Chr chromosome, UTR untranslated region, wt wild type