Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0308, USA.
Biochemistry. 2011 Jul 12;50(27):6041-52. doi: 10.1021/bi200362w. Epub 2011 Jun 15.
Recent work has demonstrated that 4-hydroxybenzoic acid is the in vivo precursor to the 1-(4-aminophenyl)-1-deoxy-D-ribitol (APDR) moiety present in the C(1) carrier coenzyme methanopterin present in the methanogenic archaea. For this transformation to occur, the hydroxyl group of the 4-hydroxybenzoic acid must be replaced with an amino group at some point in the biosynthetic pathway. Using stable isotopically labeled precursors and liquid chromatography with electrospray-ionization mass spectroscopy, the first step of this transformation in Methanocaldococcus jannaschii occurs by the reaction of 4-hydroxybenzoic acid with phosphoribosyl pyrophosphate (PRPP) to form 4-(β-d-ribofuranosyl)hydroxybenzene 5'-phosphate (β-RAH-P). The β-RAH-P then condenses with l-aspartate in the presence of ATP to form 4-(β-d-ribofuranosyl)-N-succinylaminobenzene 5'-phosphate (β-RFSA-P). Elimination of fumarate from β-RFSA-P produces 4-(β-D-ribofuranosyl)aminobenzene 5'-phosphate (β-RFA-P), the known precursor to the APDR moiety of methanopterin [White, R. H. (1996) Biochemistry 35, 3447-3456]. This work represents the first biochemical example of the conversion of a phenol to an aniline.
最近的研究工作表明，4- 羟基苯甲酸是 1-(4- 氨基苯基）-1-脱氧-D-核糖醇（APDR）部分在产甲烷古菌中存在的 C（1）载体辅酶亚甲基四氢叶酸的体内前体。为了发生这种转化，4- 羟基苯甲酸的羟基必须在生物合成途径的某个点被氨基取代。使用稳定同位素标记的前体和带有电喷雾电离质谱的液相色谱，Methanocaldococcus jannaschii 中这一转化的第一步是通过 4- 羟基苯甲酸与磷酸核糖焦磷酸（PRPP）反应形成 4-（β-D- 核糖呋喃基）羟基苯 5'- 磷酸（β-RAH-P）。然后，β-RAH-P 在 ATP 的存在下与 l-天冬氨酸缩合，形成 4-（β-D- 核糖呋喃基）-N-琥珀酰氨基苯 5'- 磷酸（β-RFSA-P）。β-RFSA-P 中延胡索酸的消除产生 4-（β-D- 核糖呋喃基）氨基苯 5'- 磷酸（β-RFA-P），这是亚甲基四氢叶酸的 APDR 部分的已知前体[White，RH（1996）生物化学 35，3447-3456]。这项工作代表了将苯酚转化为苯胺的第一个生化实例。
