AN INDUCIBLE TRYPTOPHAN SYNTHETASE IN TRYPTOPHAN AUXOTROPHS OF ESCHERICHIA COLI
AN INDUCIBLE TRYPTOPHAN SYNTHETASE IN TRYPTOPHAN AUXOTROPHS OF ESCHERICHIA COLI
复制标题
DOI：
10.1073/pnas.48.8.1431
复制
发表时间：
1962-01-01
影响因子：
11.1
通讯作者：
SNELL, EE
中科院分区：
文献类型：
--
作者：
NEWTON, WA;SNELL, EE
3株不同的E.大肠杆菌含有色氨酸合成酶（TSase），其由高浓度的色氨酸诱导。该酶的诱导性质是导致突变体生长中吲哚不能取代色氨酸的原因。诱导型TSase催化吲哚加丝氨酸合成色氨酸，但不催化吲哚甘油磷酸加丝氨酸合成色氨酸，并且不水解吲哚甘油磷酸。这表明该酶不同于大肠杆菌可阻遏TS酶的A或B组分。杆菌一个单一的机制可以控制2种不同的蛋白质的合成，负责2种活性或一个单一的蛋白质可能具有两种催化活性。
Tryptophan-re-quiring mutants of 3 different strains of E. coli contain a tryptophan synthetase (TSase) that is induced by high concentrations of tryptophan. The inducible nature of the enzyme is responsible for the inability of indole to substitute for tryptophan in growth of the mutants. The inducible TSase catalyzes synthesis of tryptophan from indole plus serine but not from indoleglycerol-phosphate plus serine, and it does not hydrolyze indoleglycerol-phosphate. This indicates that this enzyme is different from either the A or the B component of the repressible TSase of E. coli. A single mechanism may control the synthesis of 2 distinct proteins responsible for the 2 activities or a single protein may possess both catalytic activities.