Caroline D F, Davis R H
J Bacteriol. 1969 Dec;100(3):1378-84. doi: 10.1128/jb.100.3.1378-1384.1969.
The regulation of several enzymes involved in pyrimidine biosynthesis in Neurospora crassa has been studied. Elevation of ATCase (l-aspartate carbamoyltransferase) activity is found in all pyrimidine-requiring mutants when they are starved for uridine. DHOase (dihydroorotase) is an unstable enzyme, and it is impossible to conclude what type of regulation, if any, controls this enzyme. DHOdehase (dihydroorotate dehydrogenase) activity shows a marked elevation in uridine-starved pyr-2 cultures, a mutant blocked late in the pathway. Several mutants blocked early in the pathway show much smaller increases in DHOdehase activity and possible explanations for this are discussed. Differences in the modes of regulation of the pyrimidine biosynthetic pathways in various organisms are compared.
人们已经对粗糙脉孢菌中参与嘧啶生物合成的几种酶的调控进行了研究。当所有需要嘧啶的突变体缺乏尿苷时，天冬氨酸转氨甲酰酶（ATCase）的活性会升高。二氢乳清酸酶（DHOase）是一种不稳定的酶，因此无法确定是否存在以及何种类型的调控作用于该酶。二氢乳清酸脱氢酶（DHOdehase）的活性在缺乏尿苷的pyr - 2培养物中显著升高，pyr - 2是该代谢途径后期受阻的一个突变体。该代谢途径早期受阻的几个突变体中，DHOdehase活性的增加幅度要小得多，并对其原因进行了讨论。文中还比较了不同生物体中嘧啶生物合成途径调控模式的差异。
