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Properties of alpha-aminoisobutyric acid transport in a thermophilic microorganism.
- Source :
-
Journal of bacteriology [J Bacteriol] 1974 May; Vol. 118 (2), pp. 414-24. - Publication Year :
- 1974
-
Abstract
- Uptake of alpha-aminoisobutyric acid (AIB) by a leucine-tyrosine auxotroph of a thermophilic microorganism starved for leucine was studied. AIB was taken up by the cells against a substantial concentration gradient (300:1) and was present there in a free and unchanged form. Various energy inhibitors and sulfhydryl reagents strongly inhibited the accumulation of AIB. AIB uptake obeyed saturation kinetics, and the Lineweaver-Burk plot is characterized by a biphasic curve. AIB most probably shares a common transport system(s) with alanine, serine, and glycine. A mutant defective in l-alanine uptake was isolated by using the suicide effect due to accumulation of the tritiated substrate. The mutant also exhibited impaired transport activity towards AIB, glycine, and l-serine, but not to phenylalanine or valine. The transport of AIB, glycine, l-alanine, and l-serine was induced by d-alanine (5 x 10(-3) M) during growth in a succinate- and ammonia-containing medium. De novo protein synthesis was required for the induction of AIB transport; the induction was inhibited when growth occurred in glucose-containing media. The apparent differential rate of synthesis of the AIB transport system was decreased considerably in glucose-grown cells as compared to succinate-grown cells. A common genetic basis of either the regulatory or structural nature for the transport of AIB, alanine, glycine, and serine in a thermophilic microorganism is suggested.
- Subjects :
- Amino Acids metabolism
Amino Acids pharmacology
Azides pharmacology
Bacteria growth & development
Biological Transport, Active
Carbon Radioisotopes
Chromatography, Paper
Culture Media
Cyanides pharmacology
Dinitrophenols pharmacology
Glucose metabolism
Hot Temperature
Leucine metabolism
Mutation
Spectrophotometry
Succinates metabolism
Sulfhydryl Reagents pharmacology
Tritium
Tyrosine metabolism
Aminoisobutyric Acids metabolism
Bacteria metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9193
- Volume :
- 118
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Journal of bacteriology
- Publication Type :
- Academic Journal
- Accession number :
- 4828307
- Full Text :
- https://doi.org/10.1128/jb.118.2.414-424.1974