Enzymatic properties of the purified putA protein from Salmonella typhimurium.

In the previous paper (Menzel, R., and Roth, J. (1981) J. Biol. Chem. 256, 9755-9761) we have described the purification of a protein, the putA gene product, which has both proline oxidase and pyrroline-5-carboxylic acid dehydrogenase activities. In this paper we demonstrate that these enzyme activities are distinct with respect to a number of characteristics. The oxidase activity proceeds by a ping-pong mechanism involving the reduction of an enzyme-bound flavin. The dehydrogenase activity utilizes an ordered reaction mechanism.