Hutchinson M A, Belser W L
J Bacteriol. 1969 Apr;98(1):109-15. doi: 10.1128/jb.98.1.109-115.1969.
In Serratia marcescens, the tryptophan biosynthetic enzymes were formed coordinately. A number of tryptophan auxotrophs showed single biochemical lesions; several mutants showed pleiotropic effects. Sucrose density gradient centrifugation revealed an unique pattern of migration of the tryptophan biosynthetic enzymes. The repression response of the Serratia enzymes to exogenous tryptophan was fivefold more sensitive than that found in Escherichia coli. When this information is contrasted with the available information on the other Enterobacteriaceae, one is compelled to conclude that S. marcescens enjoys a rather marked evolutionary divergence from the other enteric organisms.
在粘质沙雷氏菌中,色氨酸生物合成酶是协同形成的。许多色氨酸营养缺陷型菌株表现出单一的生化损伤;几个突变体表现出多效性效应。蔗糖密度梯度离心揭示了色氨酸生物合成酶独特的迁移模式。粘质沙雷氏菌酶对外源色氨酸的阻遏反应比大肠杆菌中的反应敏感五倍。当将这些信息与其他肠杆菌科的现有信息进行对比时,人们不得不得出结论,粘质沙雷氏菌与其他肠道生物相比具有相当明显的进化差异。