Sargent M L, Woodward D O
J Bacteriol. 1969 Feb;97(2):867-72. doi: 10.1128/jb.97.2.867-872.1969.
A spontaneous, single-gene mutation responsible for a total lack of invertase activity in Neurospora crassa is described. The mutation is believed to lie in the structural gene for invertase, since an immunologically cross-reacting protein is made by the mutant strain. In addition, there was no evidence for a defect in regulation of invertase activity or synthesis by the following criteria. (i) The invertaseless condition was recessive in heterokaryons; (ii) no invertase inhibitor was found in mutant extracts by mixing experiments; and (iii) none of the several sugars able to induce activity in wild-type strains was able to induce activity in the mutant strain. It was also discovered that most of the wild-type enzyme (55 to 75%) cannot be washed free from the rapidly sedimenting cell debris. This finding provided additional support for the hypothesis that Neurospora invertase is located within or about the cell wall.
本文描述了一种导致粗糙脉孢菌完全缺乏转化酶活性的自发单基因突变。由于突变菌株能产生免疫交叉反应蛋白，所以该突变被认为位于转化酶的结构基因中。此外，根据以下标准，没有证据表明转化酶活性或合成的调控存在缺陷。(i) 在异核体中，无转化酶状态是隐性的；(ii) 通过混合实验在突变提取物中未发现转化酶抑制剂；(iii) 几种能在野生型菌株中诱导活性的糖，均不能在突变菌株中诱导活性。还发现，大部分野生型酶（55%至75%）无法从快速沉降的细胞碎片中洗脱下来。这一发现为粗糙脉孢菌转化酶位于细胞壁内或细胞壁周围的假说提供了额外支持。
