ORNITHINE ACTIVATING ENZYME FROM BACILLUS BREVIS

Current studies on biosynthesis of gramicidin S have revealed that the peptide is synthesized by cell-free system from Bacillus brevis and the mechanism of its formation is different from that in usual protein synthesis, i.e. there is no participation of any RNA or influence of any inhibitor on protein biosynthesis (Yukioka et al., 1965; Bhagavan et al., 1966; Spaeren et al., 1967; Tomino et al., 1967). The activations of the five constituent amino acids were each shown to occur by amino acid dependent PPi-ATP exchange reactions, but amino acyl-tRNA formation was not observed (Gevers et al., 1968). Among these reactions, it is most interesting to study the mechanism of activation of ornithine, since ornithine is not involved in usual protein biosynthesis. In this paper, a procedure for partial purification of the ornithine activating enzyme from extracts of Bacillus brevis Nagano, some properties of the enzyme and also the relation of this enzyme to the formation of gramicidin S are presented. © 1968.