Vallari D S, Rock C O
Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.
J Bacteriol. 1987 Dec;169(12):5795-800. doi: 10.1128/jb.169.12.5795-5800.1987.
Escherichia coli mutants conditionally defective in the conversion of pantothenate to coenzyme A were isolated and characterized. The gene was designated coaA and localized between argEH and rpoB near min 90 of the chromosome. The coaA15(Ts) mutation caused a temperature-sensitive growth phenotype and temperature-dependent inactivation of pantothenate kinase activity assayed both in vivo and in vitro. At 30 degrees C, coaA15(Ts) extracts contained less than 20% of the wild-type pantothenate kinase activity; the kinase had near normal kinetic constants for the substrates ATP and pantothenate and was inhibited by coenzyme A to the same degree as the wild-type enzyme. These data define the coaA gene as the structural gene for pantothenate kinase.
分离并鉴定了在泛酸盐转化为辅酶A过程中存在条件缺陷的大肠杆菌突变体。该基因被命名为coaA，定位于染色体90分钟附近的argEH和rpoB之间。coaA15(Ts)突变导致温度敏感型生长表型以及体内和体外检测的泛酸盐激酶活性的温度依赖性失活。在30℃时，coaA15(Ts)提取物中野生型泛酸盐激酶活性不到20%；该激酶对底物ATP和泛酸盐具有接近正常的动力学常数，并被辅酶A抑制的程度与野生型酶相同。这些数据将coaA基因定义为泛酸盐激酶的结构基因。
