Identification of the Myxococcus xanthus 59-kDa membrane-associated GTP-binding protein as a proton-translocating ATPase

Five GTP-binding proteins have been detected in Myxococcus xanthus by photoaffinity cross-linking with azido-GTP [Muñoz-Dorado et al., J. Biol. Chem. 265 (1990a) 2702-2706]. One of them, the 59-kDa membrane-associated GTP-binding protein, has been purified. The N-terminal sequence of a 10-kDa fragment from the protease V8 digestion of the purified protein has been determined and degenerate oligodeoxyribonucleotides based on that sequence have been used to isolate and clone the gene that encodes the GTP-binding protein. The gene was sequenced and further analysis of the sequence revealed that the protein encoded by this gene shows very high homology with the a subunit of protontranslocating ATPases.