Saier M H, Feucht B U, Hofstadter L J
J Biol Chem. 1976 Feb 10;251(3):883-92.
The uptake of various carbohydrates and the synthesis of adenosine 3':5'-monophosphate (cyclic AMP) are subject to inhibition by sugar substrates of the phosphoenolpyruvate:sugar phosphotransferase system in Escherichia coli. The induced synthesis of the sugar-specific components of the phosphotransferase system was studied and correlated with the induction of regulatory interactions controlling glycerol uptake and net cyclic AMP synthesis. Activities of the Enzyme II complexes specific for glucose, fructose, and mannitol were measured both in vivo and in vitro. These activities were induced 8- to 40-fold by growth in the presence of the appropriate substrate-inducers. Cross inducer specificities were noted. Maximal inhibition of glycerol uptake and cyclic AMP synthesis by a sugar substrate of the phosphotransferase system required induction of the Enzyme II complex specific for that sugar and was abolished by mutations which destroyed Enzyme II activity. The inducer specificities of the regulatory systems and of the Enzymes II were found to be the same. A mutation which depressed the cellular activity of Enzyme I of the phosphotransferase system did not relieve sensitivity to inhibition. The results suggest that adenylate cyclase and several carbohydrate permeases are subject to coordinate regulation by a mechanism which depends on the catalytic activities of the protein components of the phosphotransferase system.
在大肠杆菌中,磷酸烯醇丙酮酸:糖磷酸转移酶系统的糖底物会抑制各种碳水化合物的摄取以及3':5'-单磷酸腺苷(环磷酸腺苷)的合成。对磷酸转移酶系统糖特异性成分的诱导合成进行了研究,并将其与控制甘油摄取和环磷酸腺苷净合成的调节相互作用的诱导相关联。在体内和体外测量了对葡萄糖、果糖和甘露醇具有特异性的酶II复合物的活性。通过在适当的底物诱导剂存在下生长,这些活性被诱导了8至40倍。观察到了交叉诱导剂特异性。磷酸转移酶系统的糖底物对甘油摄取和环磷酸腺苷合成的最大抑制需要诱导对该糖具有特异性的酶II复合物,并且被破坏酶II活性的突变所消除。发现调节系统和酶II的诱导剂特异性是相同的。降低磷酸转移酶系统酶I细胞活性的突变并不能消除对抑制的敏感性。结果表明,腺苷酸环化酶和几种碳水化合物通透酶受到一种机制的协调调节,该机制依赖于磷酸转移酶系统蛋白质成分的催化活性。