Phosphofructokinase B (PfkB) belongs to the ribokinase family, which uses the phosphorylated sugar as substrate, and catalyzes fructose-6-phosphate into fructose-1,6-diphosphate. However, the structural basis of Mycobacterium marinum PfkB is not clear. Here, we found that the PfkB protein was monomeric in solution, which was different from most enzymes in this family. The crystal structure of PfkB protein from M. marinum was solved at a resolution of 2.21 Å. The PfkB structure consists of two domains, a major three-layered α/β/α sandwich-like domain characteristic of the ribokinase-like superfamily, and a second domain composed of four-stranded β sheets. Structural comparison analysis suggested that residues G236, A237, G238, and D239 could be critical for ATP catalysis and substrate binding of PfkB. Our current work provides new insights into understanding the mechanism of the glycolysis in M. marinum.

磷酸果糖激酶 B (PfkB) 属于核糖激酶家族，以磷酸化糖为底物，将 6-磷酸果糖催化为 1,6-二磷酸果糖。然而，海分枝杆菌PfkB的结构基础尚不清楚。在这里，我们发现 PfkB 蛋白在溶液中是单体的，这与该家族中的大多数酶不同。从PfkB蛋白的晶体结构海分枝杆菌分辨率为 2.21 Å。PfkB 结构由两个结构域组成，一个主要的三层 α/β/α 三明治样结构域是核糖激酶样超家族的特征，第二个结构域由四链 β 折叠组成。结构比较分析表明，残基 G236、A237、G238 和 D239 可能对 PfkB 的 ATP 催化和底物结合至关重要。我们目前的工作为理解海藻糖酵解的机制提供了新的见解。