Fig. 3

Processing of different mitochondrial targeting sequences fused to NifU in different culture conditions and analysis of nif-related gene expression. a Anti-NifU WB showing the processing of the different mitochondrial targeting signals of NifU (W303 strains with constructs inserted into YPRCΔ15) in exponentially growing cultures containing glucose as carbon source. The lower panel shows the corresponding membrane Coomassie stained as a loading control. b Anti-His WB analysis of nif-related gene expression in W303 exponentially growing cultures (two left panels) or saturated cultures (OD₆₀₀ ~ 10, right panel) using glucose as the carbon source. All strains carried the nif genes inserted into the YPRCΔ15 locus. The lower panels show the corresponding membrane Coomassie stained as a loading control. c Same as (a), but using glycerol as the carbon source. d Growth curve of a S. cerevisiae W303 culture growing with glucose as the carbon source (upper panel) and glucose determination in the media (lower panel). Note the growth lag that coincides with the exhaustion of glucose and with a probable adaptation of the culture to ethanol respiration. e Processing of different mitochondrial targeting signals of NifU in W303 cultures containing glucose as carbon source at an OD₆₀₀ of 12 (post-glucose exhaustion). The lower panel shows the corresponding membrane Coomassie stained as a loading control