THE ATP-SYNTHASE (F1FO) OF STREPTOMYCES-LIVIDANS - SEQUENCING OF THE ATP-OPERON AND PHYLOGENETIC CONSIDERATIONS WITH SUBUNIT-BETA

The DNA encoding the subunits of the ATP synthase (F1F0) of Steptomyce s lividans 66 strain 1326 was identified using oligodeoxyribonucleotid e probes derived from the N-terminal sequence of subunit gamma of the F-1 complex. The complete nucleotide sequence of the operon was determ ined. The ntp operon contains nine genes, atpIBEFHAGDC, encoding the e ight structural components of the ATP synthase complex and the i prote in, a polypeptide of unknown function, The gene order found is identic al to that in other non-photosynthetic eubacteria, The determination o f the N-terminal amino acid (aa) sequences of the F-1 subunits a, beta , gamma, delta and epsilon allowed us to identify the translational st art points and to define the primary structures of the proteins. The a a sequence deduced for subunit delta revealed an N-terminal extension of about 90 aa, which is not present in any delta subunit or OSCP (oli gomycin sensitivity-conferral protein) of other species studied so far . The phylogenetic relationship of eu- and archaebacteria was investig ated using sequencing data of the highly conserved beta subunit of dif ferent ATP synthases including that of S. lividans. The calculations r evealed that S. lividans beta does not form a phylogenetic group toget her with the Gram(+) taxa of low G+C contents, but is more closely rel ated to the beta subunit of Rhodobacteria.