Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
J Am Chem Soc. 2011 Jun 8;133(22):8531-3. doi: 10.1021/ja2030728. Epub 2011 May 11.
The stereochemistry of a phenylalanine aminomutase (PAM) on the andrimid biosynthetic pathway in Pantoea agglomerans (Pa) is reported. PaPAM is a member of the 4-methylidene-1H-imidazol-5(4H)-one (MIO)-dependent family of catalysts and isomerizes (2S)-α-phenylalanine to (3S)-β-phenylalanine, which is the enantiomer of the product made by the mechanistically similar aminomutase TcPAM from Taxus plants. The NH(2) and pro-(3S) hydrogen groups at C(α) and C(β), respectively, of the substrate are removed and interchanged completely intramolecularly with inversion of configuration at the migration centers to form β-phenylalanine. This is a contrast to the retention of configuration mechanism followed by TcPAM.
报道了成团泛菌（Pantoea agglomerans）中安德里米德生物合成途径上的苯丙氨酸氨甲酰基转移酶（PAM）的立体化学。PaPAM 是 4-亚甲基-1H-咪唑-5(4H)-酮（MIO）依赖性酶家族的成员，可将（2S）-α-苯丙氨酸异构化为（3S）-β-苯丙氨酸，这与来自红豆杉属植物的结构类似的氨甲酰基转移酶 TcPAM 生成的产物的对映体相同。底物的 Cα 和 Cβ 上的 NH2 和 pro-(3S) 氢原子分别被去除，并在迁移中心的构型翻转下完全在分子内交换，形成β-苯丙氨酸。这与 TcPAM 遵循的构型保留机制形成对比。
