This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hoshino, T Articles by Kageyama, M Search for Related Content PubMed PubMed Citation Articles by Hoshino, T Articles by Kageyama, M

 Previous Article  |  Next Article 

J Bacteriol. 1982 August; 151(2): 620-628

Mutational separation of transport systems for branched-chain amino acids in Pseudomonas aeruginosa.

ABSTRACT

Several types of Pseudomonas aeruginosa mutants defective in the transport systems for branched-chain amino acids were isolated by selection for resistance to 5',5',5'-DL-trifluoroleucine, a leucine analog, under certain conditions. Mutants resistant to trifluoroleucine in the absence of Na+ were defective in the high-affinity system. These mutants fell into two classes. One class showed a defect in the production of a periplasmic binding protein for leucine, isoleucine, valine, alanine, and threonine, and the other showed normal production of the binding protein as determined by a binding assay and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Properties of the former class of mutants have been partly described (T. Hoshino and M. Kageyama, J. Bacteriol. 141:1055-1063, 1980). Mutants selected for resistance to trifluoroleucine with Na+ and an excess amount of alanine showed a defect in the low-affinity system. Membrane vesicles prepared from such a mutant lost the transport activity for leucine. A mutant which showed increased activity of the low-affinity system with a defect in the high-affinity system was obtained from strain PML1453 (high-affinity system defective) by selecting for utilization of isoleucine as a carbon source.