Tilby M J
J Gen Microbiol. 1976 Mar;93(1):126-32. doi: 10.1099/00221287-93-1-126.
Thirty-one tryptophan-requiring mutants of Coprinus lagopus have been assigned by genetic and complementation analyses to four loci designated trp-I, trp-2, trp-3 and trp-4. The trp-1 and trp-3 loci were located in group III and trp-2 in group G of the linkage map. The trp-4 locus showed no linkage to the other trp loci or to markers in three additional linkage groups tested. From auxanographic tests and a study of accumulated biosynthetic intermediates, the enzymes controlled by each locus have been provisionally assigned. The trp-2 and trp-3 loci both appear necessary for anthranilate synthetase activity since mutants accumulated no intermediates. Only the trp-3 mutant could utilize anthranilic acid, therefore the trp-2 locus must also be involved in a subsequent step in the pathway. The trp-4 mutants utilized indole and accumulated anthranilic acid, and hence this locus is involved in the conversion of anthranilic acid to indoleglycerol phosphate. The trp-1 mutants utilized only tryptophan and accumulated indoleglycerol phosphophate and anthranilic acid. They are therefore blocked in the final steps of the pathway catalysed by tryptophan synthetase.
通过遗传分析和互补分析，已将31个需要色氨酸的鬼伞属突变体定位到四个基因座，分别命名为trp-I、trp-2、trp-3和trp-4。trp-1和trp-3基因座位于连锁图的第三组，trp-2位于G组。trp-4基因座与其他trp基因座或另外三个测试连锁群中的标记均无连锁关系。通过营养缺陷型分析和对积累的生物合成中间体的研究，已初步确定了每个基因座所控制的酶。trp-2和trp-3基因座对于邻氨基苯甲酸合成酶活性似乎都是必需的，因为突变体没有积累中间体。只有trp-3突变体能利用邻氨基苯甲酸，因此trp-2基因座一定也参与了该途径的后续步骤。trp-4突变体能利用吲哚并积累邻氨基苯甲酸，因此该基因座参与邻氨基苯甲酸向吲哚甘油磷酸的转化。trp-1突变体只利用色氨酸，并积累吲哚甘油磷酸和邻氨基苯甲酸。因此，它们在色氨酸合成酶催化的途径的最后步骤中受阻。
