Thialysine-resistant mutants and uptake of lysine inSchizosaccharomyces pombe

✍ Scribed by H. Sychrová; M. R. Chevallier; J. Horák; A. Kotyk

• Publisher: Springer-Verlag
• Year: 1992
• Tongue: English
• Weight: 510 KB
• Volume: 21
• Category: Article
• ISSN: 0172-8083
• DOI: 10.1007/bf00351694

✦ Synopsis

Mutants defective in lysine transport were isolated and characterized. After UV-mutagenesis colonies resistant to thialysine, a toxic analogue of lysine, were isolated and L-lysine uptake into the mutant strains was analyzed. Among the thiatysine-resistant strains a group of mutants was found, where the half-saturation constant, Kr, of the high-affinity transport system for lysine was higher than in the wild-type, the high-affinity transport system for basic amino acids being specifically affected. This was confirmed by a complementation test in which all the thialysine-resistant strains with a higher KT for" lysine uptake belonged to one complementation group. Kinetic and genetic analysis showed that our mutants were identical with can1-1 mutants, showing that a single high-affinity system for the transport of basic amino acids exists in S. pombe.