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 [Munoz-Dorado et al., J. Bi ol. Chem. 265 (1990a) 2702-2706]. One of them, the 59-kDa membrane-ass ociated GTP-binding protein, has been purified. The N-terminal sequenc e of a 10-kDa fragment from the protease V8 digestion of the purified protein has been determined and degenerate oligodeoxyribonucleotides b ased on that sequence have been used to isolate and clone the gene tha t encodes the GTP-binding protein. The gene was sequenced and further analysis of the sequence revealed that the protein encoded by this gen e shows very high homology with the or subunit of proton-translocating ATPases.