Fig. 1.

Schematic representation of human frataxin processing and constructs. (A) Frataxin precursor (1–210) (p), its intermediate processing product (42–210) (i), mature form 1 (56–210) (m₁), and mature form 2 (81–210) (m₂). (B) Three different constructs expressing frataxin in the pABPURO vector with or without mitochondrial import sequence: full-length human frataxin (frataxin^1–210), frataxin preceded by the 14-aa mitochondrial import sequences of the T. brucei dihydrolipoamide dehydrogenase (frataxin^Tb-56–210), and frataxin without import signal (frataxin^56–210). (C) Three constructs expressing different site-specific mutants of full-length of frataxin in the pABPURO vector. The arginines 53, 54, and 79 and lysine 80 were replaced with glycines, producing constructs frataxin_56, frataxin_81, and frataxin_56 + 81. Arrowheads and arrows indicate aa positions and MPP cleavage sites, respectively.