The biogenetic anatomy of vitamin B-6 - A C-13 NMR investigation of the biosynthesis of pyridoxol in Escherichia coli
The biogenetic anatomy of vitamin B-6 - A C-13 NMR investigation of the biosynthesis of pyridoxol in Escherichia coli
复制标题
DOI：
10.1074/jbc.271.48.30426
复制
发表时间：
1996-11-29
影响因子：
4.8
通讯作者：
Spenser, ID
中科院分区：
文献类型：
--
作者：
Hill, RE;Himmeldirk, K;Spenser, ID
通过C-13键标记底物的掺入实验，随后通过C-13 NMR光谱分析，表明两种化合物，1-脱氧-D-木酮糖（12）和4-羟基-L-苏氨酸（13），在大肠杆菌中作为吡哆醇（维生素B-6）（1）的前体。这两种化合物共同构成了维生素的整个C8 N骨架。1-脱氧-D-木酮糖提供完整的C-5单元，吡哆醇的C-2 '，2，3，4，4'。4-羟基-L-苏氨酸在提供完整的C3 N单元N-1、C-6、5、5 '时经历脱羧。这两种前体最终都来源于葡萄糖。衍生自1-脱氧-D-木酮糖的吡哆醇的C-5单元来源于磷酸丙糖（产生C-3，4，4 '）与异麦芽糖酸（其脱羧产生C-2'，2）的结合。D-赤藓糖酸（11）进入C-3单元C-6，5，5 '，因此是从葡萄糖到4-羟基-L-苏氨酸的中间体。
It is shown by incorporation experiments with C-13 bond-labeled substrates, followed by analysis by means of C-13 NMR spectroscopy, that two compounds, 1-deoxy-D-xylulose (12) and 4-hydroxy-L-threonine (13), serve as precursors of pyridoxol (vitamin B-6) (1) in Escherichia coli. Together, these two compounds account for the entire C8N skeleton of the vitamin. 1-Deoxy-D-xylulose supplies the intact C-5 unit, C-2',2,3,4,4' of pyridoxol. 4-Hydroxy-L-threonine undergoes decarboxylation in supplying the intact C3N unit, N-1,C-6,5,5'. Both precursors are ultimately derived from glucose. The C-5 unit of pyridoxol that is derived from l-deoxy-D-xylulose originates by union of a triose phosphate (yielding C-3,4,4') with pyruvic acid (which decarboxylates to yield C-2',2). D-Erythroate (11) enters the C-3 unit, C-6,5,5', and is therefore an intermediate on the route from glucose into 4-hydroxy-L-threonine.