Ames G F, Lever J
Proc Natl Acad Sci U S A. 1970 Aug;66(4):1096-103. doi: 10.1073/pnas.66.4.1096.
The high-affinity (K(m) = 3 x 10(-8) M) transport system for histidine in Salmonella typhimurium has been resolved into three components: J, K, and P. J, which is a histidine-binding protein released by osmotic shock, is specified by the hisJ gene: hisJ mutants lack the binding protein and are defective in histidine transport. Another class of mutants-dhuA, which is closely linked to hisJ-has five times the normal level of binding protein and has an increased rate of histidine transport. P, which is a protein specified by the hisP gene, is required for J binding protein to be operative in transport. hisP mutants, though defective in transport, have normal levels of J binding protein. K, a third transport component, works in parallel to J, and also requires the P protein in order to be operative in transport. A second histidine-binding protein has been found but its relation to K is unclear. hisJ, dhuA, and hisP have been mapped and are in a cluster (near purF) on the S. typhimurium chromosome.
鼠伤寒沙门氏菌中组氨酸的高亲和力(K(m)=3×10⁻⁸M)转运系统已被解析为三个组分:J、K和P。J是一种通过渗透休克释放的组氨酸结合蛋白,由hisJ基因编码:hisJ突变体缺乏结合蛋白,并且在组氨酸转运方面存在缺陷。另一类突变体——与hisJ紧密连锁的dhuA——其结合蛋白水平是正常水平的五倍,并且组氨酸转运速率增加。P是一种由hisP基因编码的蛋白,是J结合蛋白在转运中发挥作用所必需的。hisP突变体虽然在转运方面存在缺陷,但J结合蛋白水平正常。K是第三个转运组分,与J并行发挥作用,并且也需要P蛋白才能在转运中发挥作用。已发现第二种组氨酸结合蛋白,但其与K的关系尚不清楚。hisJ、dhuA和hisP已被定位,并且在鼠伤寒沙门氏菌染色体上的一个簇中(靠近purF)。