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

Abstract

The DNA encoding the subunits of the ATP synthase (F1F0) of Steptomyces lividans 66 strain 1326 was identified using oligodeoxyribonucleotide probes derived from the N-terminal sequence of subunit gamma of the F-1 complex. The complete nucleotide sequence of the operon was determined. The ntp operon contains nine genes, atpIBEFHAGDC, encoding the eight structural components of the ATP synthase complex and the i protein, a polypeptide of unknown function, The gene order found is identical to that in other non-photosynthetic eubacteria, The determination of the N-terminal amino acid (aa) sequences of the F-1 subunits a, beta, gamma, delta and epsilon allowed us to identify the translational start points and to define the primary structures of the proteins. The aa sequence deduced for subunit delta revealed an N-terminal extension of about 90 aa, which is not present in any delta subunit or OSCP (oligomycin sensitivity-conferral protein) of other species studied so far. The phylogenetic relationship of eu- and archaebacteria was investigated using sequencing data of the highly conserved beta subunit of different ATP synthases including that of S. lividans. The calculations revealed that S. lividans beta does not form a phylogenetic group together with the Gram(+) taxa of low G+C contents, but is more closely related to the beta subunit of Rhodobacteria.