A Three Enzyme Pathway for 2-Amino-3-hydroxycyclopent-2-enone Formation and Incorporation in Natural Product Biosynthesis
作者:Wenjun Zhang、Megan L. Bolla、Daniel Kahne、Christopher T. Walsh
DOI:10.1021/ja1002845
日期:2010.5.12
A number of natural products contain a 2-amino-3-hydroxycyclopent-2-enone five membered ring, termed C(5)N, which is condensed via an amide linkage to a variety of polyketide-derived polyenoic acid scaffolds. Bacterial genome mining indicates three tandem ORFs that may be involved in C(5)N formation and subsequent installation in amide linkages. We show that the protein products of three tandem ORFs
许多天然产物含有 2-氨基-3-羟基环戊-2-烯酮五元环,称为 C(5)N,它通过酰胺键缩合到各种聚酮化合物衍生的多烯酸支架上。细菌基因组挖掘表明可能参与 C(5)N 形成和随后安装在酰胺键中的三个串联 ORF。我们展示了来自 Streptomyces aizunenesis NRRL-B-11277 中 ECO-02301 生物合成基因簇的三个串联 ORF (ORF33-35) 的蛋白质产物,当从大肠杆菌中纯化时,证明了 C(5)N 形成所需的酶活性和酰胺连接。首先,琥珀酰-CoA 和甘氨酸通过专用的 PLP 依赖性 ALA 合酶 (ORF34) 缩合生成 5-氨基乙酰丙酸 (ALA)。然后通过酰基辅酶A连接酶(ORF35)通过ALA-AMP中间体将ALA转化为ALA-CoA。ALA-CoA 是不稳定的,在用于非途径环化成 2,5-哌啶二酮的孵育条件下,其半衰期约为 10 分钟。ALA