Evolutionary relationship between Enterobacteriaceae: comparison of the ATP synthases (F1F0) of Escherichia coli and Klebsiella pneumoniae.

The ATP synthase complex of Klebsiella pneumoniae (KF1F0) has been purified and characterized. SDS-gel electrophoresis of the purified F1F0 complexes revealed an identical subunit pattern for E. coli (EF1F0) and K. pneumoniae. Antibodies raised against EF1 complex and purified EF0 subunits recognized the corresponding polypeptides of EF1F0 and KF1F0 in immunoblot analysis. Protease digestion of the individual subunits generated an identical cleavage pattern for subunits alpha, beta, gamma, epsilon, a, and c of both enzymes. Only for subunit delta different cleavage products were obtained. The isolated subunit c of both organisms showed only a slight deviation in the amino acid composition. These data suggest that extensive homologies exist in primary and secondary structure of both ATP synthase complexes reflecting a close phylogenetic relationship between the two enterobacteric tribes.