Streptomyces peucetius var. caesius, the doxorubicin-producing strain, has two glucokinases (Glks) for glucose phosphorylation. One of them (ATP-Glk) uses adenosine triphosphate as its phosphate source, and the other one uses polyphosphate (PP). Glk regulates the carbon catabolite repression (CCR) process, as well as glucose utilization. However, in the streptomycetes, the specific role of each one of the Glks in these processes is unknown. With the use of PP- and ATP-Glk null mutants, we aimed to establish their respective role in glucose metabolism and their possible implication in the CCR. Our results supported that in S. peucetius var. caesius, both Glks allowed this strain to grow in different glucose concentrations. PP-Glk seems to be the main enzyme for glucose metabolism, and ATP-Glk is the only one involved in the CCR process affecting the levels of α-amylase and anthracycline production. Besides, analysis of Glk activities in the parental strain and the mutants revealed ATP-Glk as an enzyme negatively affected by high glucose concentrations. Although ATP-Glk utilizes only ATP as the substrate for glucose phosphorylation, probably PP-Glk can use either ATP or polyphosphate. Finally, a possible connection between both Glks may exist from the regulatory point of view.

中文翻译：

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剖析两种 Streptomyces peucetius var. 的作用。caesius 葡萄糖激酶对碳分解代谢物抑制的敏感性

Streptomyces peucetius 变种 caesius 是产生多柔比星的菌株，具有两种用于葡萄糖磷酸化的葡萄糖激酶 (Glks)。其中一种（ATP-Glk）使用三磷酸腺苷作为其磷酸盐来源，另一种使用多磷酸盐（PP）。Glk 调节碳分解代谢物抑制 (CCR) 过程以及葡萄糖利用。然而，在链霉菌中，每个 Glk 在这些过程中的具体作用尚不清楚。通过使用 PP- 和 ATP-Glk 无效突变体，我们旨在确定它们各自在葡萄糖代谢中的作用及其在 CCR 中的可能影响。我们的结果支持 S. peucetius var。caesius，两种 Glk 都允许该菌株在不同的葡萄糖浓度下生长。PP-Glk 似乎是糖代谢的主要酶，并且 ATP-Glk 是唯一参与影响 α-淀粉酶和蒽环类产生水平的 CCR 过程的分子。此外，对亲本菌株和突变体中 Glk 活性的分析表明，ATP-Glk 作为一种受高葡萄糖浓度负面影响的酶。虽然 ATP-Glk 仅使用 ATP 作为葡萄糖磷酸化的底物，但 PP-Glk 可能使用 ATP 或多磷酸盐。最后，从监管的角度来看，两个 Glk 之间可能存在联系。