Structure and properties of the phosphoenolpyruvate: glucose phosphotransferase system of oral streptococci.
Structure and properties of the phosphoenolpyruvate: glucose phosphotransferase system of oral streptococci.
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磷酸烯醇丙酮酸的结构和性质：口腔链球菌的葡萄糖磷酸转移酶系统。
DOI：
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
C. Vadeboncoeur
中科院分区：
文献类型：
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作者：
C. Vadeboncoeur
在唾液链球菌25975和各种变形链球菌的葡萄糖培养细胞的膜中，发现了三种不同的酶II，它们催化磷酸烯醇丙酮酸依赖的葡萄糖、果糖和甘露糖的磷酸化。II型甘露糖酶主要磷酸化甘露糖、葡萄糖和2-脱氧葡萄糖，II型葡萄糖酶磷酸化葡萄糖、α -甲基葡萄糖苷和2-脱氧葡萄糖。野生型或EII甘露糖阴性突变细胞的分离膜对葡萄糖和α -甲基葡萄糖苷的磷酸化不需要任何可溶性蛋白的存在，除了酶I和磷酸载体蛋白HPr。这一结果表明，口服链球菌不具有可溶性因子III葡萄糖。酶II的活性随生长糖的变化而变化，但不受协调调节。特定糖引起的变异对所有测试的菌株都是不相同的。然而，在变形链球菌菌株中，以乳糖为代价的生长总是导致酶II活性水平的显著降低。最后，用EII甘露糖阴性突变体和从其中一个突变体中分离出的假逆转物进行的实验表明，在混合物中生长的细胞对葡萄糖的优先利用取决于EII甘露糖的存在，而不是葡萄糖衍生的代谢物。
The presence of three distinct enzymes II that catalysed the phosphoenolpyruvate-dependent phosphorylation of glucose, fructose, and mannose was established in membranes of glucose-grown cells of Streptococcus salivarius 25975 and various strains of Streptococcus mutans. The enzyme II mannose phosphorylated mainly mannose, glucose, and 2-deoxyglucose, and the enzyme II glucose phosphorylated glucose, alpha-methylglucoside, and 2-deoxyglucose. The phosphoenolpyruvate-dependent phosphorylation of glucose and alpha-methylglucoside by isolated membrane of wild-type or EII mannose negative mutant cells did not require the presence of any soluble protein other than enzyme I and the phosphocarrier protein HPr. This result suggested that oral streptococci do not possess a soluble factor III glucose. The enzyme II activities varied as a function of the growth sugar but were not coordinately regulated. The variation elicited by specific sugars was not identical for all the strains tested. Nevertheless, in the case of the S. mutans strains, growth at the expense of lactose always caused a significant decrease in the level of enzyme II activities. Finally, experiments conducted with EII mannose negative mutants and also with a pseudorevertant isolated from one of these mutants indicated that the preferential utilization of glucose over lactose by cells growing in mixtures depended on the presence of the EII mannose, but not on glucose-derived metabolites.
DOI：
10.1016/s0021-9258(19)45412-4
发表时间：
1982-12
期刊：
The Journal of biological chemistry
影响因子：
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作者：
J. Stock;E. Waygood;N. Meadow;P. Postma;S. Roseman
通讯作者：
J. Stock;E. Waygood;N. Meadow;P. Postma;S. Roseman