The presence of glutamate mutase in a methanol-utilizing bacterium, Protaminobacter ruber

Cell-free extracts of a facultative methylotroph and strict aerobe, Protaminobacter ruber, could catalyze formation of beta-methylaspartate from glutamate. beta-Methylaspartate formed was further converted to mesaconate. From these results, it was found that the cells of P. ruber contained a sequential reaction system of glutamate mutase and beta-methylaspartase. The level of glutamate mutase activity was almost constant throughout the period of cultivation. When P. ruber was grown on several non-one-carbon compounds in addition to methanol as a sole carbon source, the activity of glutamate mutase was not markedly affected by the kinds of carbon sources.