Dataset for: 6-Phosphogluconolactonase is critical for the efficient functioning of the pentose phosphate pathway

In the oxidative branch of the pentose-phosphate pathway (oxPPP), a virtually ubiquitous metabolic pathway in eukaryotes and most bacteria, 6-phosphogluconolactone hydrolysis into 6-phosphogluconate is catalysed by 6-phosphogluconolactonase (Pgl) but in the absence of the latter, the oxPPP flux is thought to be maintained by spontaneous hydrolysis. However, in Deltapgl Escherichia coli, an extracellular pathway can also contribute to pentose-phosphate synthesis. This raises question as to whether a non-enzymatic reaction can compensate for the absence of 6-phosphogluconolactonase and, ultimately, on the role of 6-phosphogluconolactonase in central metabolism. Our results indicate that in the absence of Pgl, this bypass pathway accounts for the entire flux into the oxPPP, suggesting that non-enzymatic hydrolysis does not compensate for the absence of Pgl and demonstrating that Pgl is critical for an efficiently functioning oxPPP.

戊糖磷酸途径的氧化分支（oxPPP）是真核生物与多数细菌中近乎普遍存在的代谢通路，其中6-磷酸葡糖酸内酯水解生成6-磷酸葡糖酸的反应，由6-磷酸葡糖酸内酯酶（6-phosphogluconolactonase, Pgl）催化。传统认知中，当缺失该酶时，oxPPP的代谢流量可通过自发水解得以维持。然而，在Deltapgl大肠杆菌中，一条胞外通路同样可参与戊糖磷酸的合成。这引发了两项核心科学疑问：非酶促反应能否弥补6-磷酸葡糖酸内酯酶的缺失，以及该酶在中心代谢中的最终功能。本研究结果表明，在缺失Pgl的情况下，这条旁路通路承担了oxPPP的全部代谢流量，证实非酶促水解无法弥补Pgl的缺失，同时证明Pgl对于oxPPP的高效运转至关重要。