De novo biosynthesis of purine nucleotides

Purine nucleotides participate in many aspects of cellular metabolism including the structure of DNA and RNA, serving as enzyme cofactors, functioning in cellular signaling, acting as phosphate group donors, and generating cellular energy. Maintenance of the proper balance of intracellular pools of these nucleotides is critical to normal function. This occurs through a combination of de novo biosynthesis and salvage pathways for pre-existing purine bases, nucleosides and nucleotides. The de novo biosynthetic pathway for purine nucleotides is highly conserved among organisms, but its regulation and the organization of the genes encoding the enzymes vary. This fourteen step pathway contains ten steps that branch at IMP to form AMP and GMP, each in two steps. Regulation of the pathway has been well studied in microbes such as Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae, but little is known about its regulation in higher eukaryotes (metazoa, and plants). Source: https://pathway.yeastgenome.org/

嘌呤核苷酸在细胞代谢的多个方面发挥着重要作用，包括DNA和RNA的结构、作为酶的辅因子、参与细胞信号传导、充当磷酸基团供体以及产生细胞能量。维持这些核苷酸在细胞内池中的适当平衡对于正常功能至关重要。这一过程通过从头合成和回收现有嘌呤碱、核苷和核苷酸的途径实现。嘌呤核苷酸的从头合成途径在生物体之间高度保守，但其调控机制以及编码酶的基因组织却存在差异。该十四步途径包含十个步骤，在肌苷酸（IMP）处分支形成腺苷酸（AMP）和鸟苷酸（GMP），每个均为两步。该途径的调控已在诸如大肠杆菌（Escherichia coli）、枯草芽孢杆菌（Bacillus subtilis）和啤酒酵母（Saccharomyces cerevisiae）等微生物中得到深入研究，但在高等真核生物（如动物和植物）中的调控机制了解甚少。来源：https://pathway.yeastgenome.org/