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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Bussey, H. Articles by Umbarger, H. E. Search for Related Content PubMed PubMed Citation Articles by Bussey, H. Articles by Umbarger, H. E.

 Previous Article  |  Next Article 

J Bacteriol. 1970 August; 103(2): 286-294
Copyright © 1970 American Society for Microbiology. All Rights Reserved.

Biosynthesis of the Branched-Chain Amino Acids in Yeast: a Trifluoroleucine-Resistant Mutant with Altered Regulation of Leucine Uptake

^a Department of Biological Sciences, Purdue University, Lafayette, Indiana 47907

ABSTRACT

A trifluoroleucine-resistant mutant of yeast has been isolated that exhibits reduced incorporation of the analogue into protein (15%) of that in the wild type. In the mutant, uptake of the analogue and leucine into the expandable (water-extractable) pool is enhanced, passage from the expandable to the conversion (nonwater-, ethanol-extractable) pool is unaffected, and endogenous synthesis of leucine is normally regulated. Although the leucyl transfer ribonucluic acid (tRNA) synthetase appears normal, and the tRNA^leu has wild-type acceptor activities in vitro and in vivo, the level of the mutant trifluoroleucyl tRNA pool is only 2 to 3% of that in the wild type. The data support the idea of a mutation affecting passage between the conversion pool and the site of charging of the analogue. The mutation is dominant and exhibits pleiotropic effects: the first leucine biosynthetic enzyme appears nonrepressible, and the leucine, valine, and tyrosine uptake systems are constitutively elevated (three- to fourfold) in the absence of exogenous amino acids.

¹ Present address: Department of Genetics, McGill University, Montreal 2, Quebec, Canada.

This article has been cited by other articles:

• Oliveira, V. A., Vicente, M. A., Fietto, L. G., de Miranda Castro, I., Coutrim, M. X., Schuller, D., Alves, H., Casal, M., de Oliveira Santos, J., Araujo, L. D., da Silva, P. H. A., Brandao, R. L. (2008). Biochemical and Molecular Characterization of Saccharomyces cerevisiae Strains Obtained from Sugar-Cane Juice Fermentations and Their Impact in Cachaca Production. Appl. Environ. Microbiol. 74: 693-701 [Abstract] [Full Text]