Identification and mapping of a second proline permease Salmonella typhimurium

Abstract

The existence of a 2nd proline permease, gene proP, was demonstrated in S. typhimurium. Uptake assays demonstrated that this 2nd proline permease has 5-10% of the uptake rate of the putP permease, the cell''s major proline permease, when assayed at 20 .mu.M proline. Genetic mapping by Hfr and [phage] P22-mediated genetic crosses placed the 2nd proline permease gene at 92 min on the S. typhimurium genetic map, near the genes for melibiose utilization. F''-mediated complementation tests indicated that Escherichia coli also has the proP gene.