SDS PAGE analysis. SDS PAGE of the complex I preparations from the strain BW25113 (a) and BW25113 cyaY::nptI (c) and the overproduced and isolated His-tagged CyaY (b). The assignment of the individual bands to the corresponding complex I subunits is given. The band below NuoG represents a degradation product of NuoG. The lane with the preparation from the parental strain was loaded with 100 μg protein, the lane with the preparation from the deletion strain with 80 μg protein. The gel was stained with coomassie R250.