Zaret K S, Sherman F
J Bacteriol. 1985 May;162(2):579-83. doi: 10.1128/jb.162.2.579-583.1985.
In contrast to wild-type strains of the yeast Saccharomyces cerevisiae, lys2 and lys5 mutants are able to utilize alpha-aminoadipate as a primary source of nitrogen. Chattoo et al. (B. B. Chattoo, F. Sherman, D. A. Azubalis, T. A. Fjellstedt, D. Mehnert, and M. Ogur, Genetics 93:51-65, 1979) relied on this difference in the effective utilization of alpha-aminoadipate to develop a procedure for directly selecting lys2 and lys5 mutants. In this study we used a range of mutant strains and various media to determine why normal strains are unable to utilize alpha-aminoadipate as a nitrogen source. Our results demonstrate that the anabolism of high levels of alpha-aminoadipate through the biosynthetic pathway of lysine results in the accumulation of a toxic intermediate and, furthermore, that lys2 and lys5 mutants contain blocks leading to the formation of this intermediate.
与酿酒酵母的野生型菌株相比,lys2和lys5突变体能够利用α-氨基己二酸作为主要氮源。Chattoo等人(B. B. Chattoo、F. Sherman、D. A. Azubalis、T. A. Fjellstedt、D. Mehnert和M. Ogur,《遗传学》93:51 - 65,1979)利用α-氨基己二酸有效利用方面的这种差异,开发了一种直接筛选lys2和lys5突变体的方法。在本研究中,我们使用了一系列突变菌株和各种培养基,以确定正常菌株无法利用α-氨基己二酸作为氮源的原因。我们的结果表明,通过赖氨酸生物合成途径进行的高水平α-氨基己二酸的合成代谢会导致一种有毒中间体的积累,此外,lys2和lys5突变体含有导致该中间体形成的阻断。