Thialysine-resistant mutants and uptake of lysine in Schizosaccharomyces pombe.
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 thialysine-resistant strains a group of mutants was found, where the half-saturation constant, KT, 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.
Department of Membrane Transport, Czechoslovak Academy of Sciences, Prague.
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H
Sychrová
M R
MR
Chevallier
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J
Horák
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A
Kotyk
D001120:Arginine / Q000378:metabolism; D001693:Biological Transport, Active / Q000235:genetics; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D004352:Drug Resistance, Microbial / Q000235:genetics; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008239:Lysine / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism
D005971:Glutamates; C000204:S-2-aminoethyl cysteine; D018698:Glutamic Acid; D001120:Arginine; D007930:Leucine; D008239:Lysine; D003545:Cysteine