Rytka J
J Bacteriol. 1975 Feb;121(2):562-70. doi: 10.1128/jb.121.2.562-570.1975.
It was found that D-stereoisomers of natural amino acids inhibit the growth of Saccharomyces cerevisiae cells. Kinetic and genetic evidence showed that d-amino acids enter the cell by the general amino acid permease. Two classes of S. cerevisiae mutants resistant to d-amino acids were isolated. One class of mutants appeared to be defective in the general amino acid permease specified by the gene gap. In the second class, the activity of general amino acid permease was affected by ammonium ions. Mutants of the second class were isolated in a yeast strain with the general amino acid permease insensitive to the presence of ammonium ions in culture media. The mutation affecting the permease, amc, occurred in a locus unlinked to gap.
研究发现,天然氨基酸的D-立体异构体可抑制酿酒酵母细胞的生长。动力学和遗传学证据表明,D-氨基酸通过通用氨基酸通透酶进入细胞。分离出了两类对D-氨基酸具有抗性的酿酒酵母突变体。一类突变体似乎在由基因gap指定的通用氨基酸通透酶中存在缺陷。在第二类中,通用氨基酸通透酶的活性受铵离子影响。第二类突变体是在一种通用氨基酸通透酶对培养基中铵离子的存在不敏感的酵母菌株中分离得到的。影响通透酶的突变amc发生在一个与gap不连锁的基因座上。