University Hospital Heidelberg, Department of Infectious Diseases, Parasitology, Heidelberg, Germany.
FEBS Lett. 2010 Oct 8;584(19):4169-74. doi: 10.1016/j.febslet.2010.09.013. Epub 2010 Sep 17.
Most organisms synthesise the B(6) vitamer pyridoxal 5-phosphate (PLP) via the glutamine amidotransferase PLP synthase, a large enzyme complex of 12 Pdx1 synthase subunits with up to 12 Pdx2 glutaminase subunits attached. Deletion analysis revealed that the C-terminus has four distinct functionalities: assembly of the Pdx1 monomers, binding of the pentose substrate (ribose 5-phosphate), formation of the reaction intermediate I(320), and finally PLP synthesis. Deletions of distinct C-terminal regions distinguish between these individual functions. PLP formation is the only function that is conferred to the enzyme by the C-terminus acting in trans, explaining the cooperative nature of the complex.
大多数生物体通过谷氨酸酰胺转氨酶 PLP 合酶合成 B(6)维生素吡哆醛 5-磷酸（PLP），这是一个由 12 个 Pdx1 合酶亚基和多达 12 个 Pdx2 谷氨酰胺酶亚基组成的大型酶复合物。删除分析表明，C 端具有四个不同的功能：Pdx1 单体的组装、戊糖底物（核糖 5-磷酸）的结合、反应中间体 I(320)的形成，以及最终的 PLP 合成。不同 C 末端区域的缺失区分了这些单独的功能。PLP 的形成是 C 端通过反式作用赋予酶的唯一功能，这解释了复合物的协同性质。
