Fig. 2: Activity of selected NifH variants purified from mitochondria of aerobically cultured S. cerevisiae engineered strains.

a STAC-purified ScNifHAv (strain XJ4Y), ScNifHMm (strain XJ2Y), ScNifHMi (strain XJ3Y), and ScNifHHt (strain XJ1Y) proteins. The low solubility of ScNifHAv promoted binding of contaminating proteins (as column was not saturated with ScNifHAv) that were identified by peptide mass fingerprinting as: 1) Acc1p (N1P4Q3), 2 and 3) pyruvate carboxylase (N1P377), and 4) HSP70 (D2J4C2). No identification was possible for band number 5. Uncropped gels are shown in Supplementary Fig. 9. b ARA of STAC-purified ScNifHXx variants. Activity using NifHAv and NifDKAv (positive control) was 2406 ± 53 units (nmol ethylene formed per min and mg of NifDKAv). Data represent mean values (n = 2 technical replicates).