植物和细菌中类黄酮柚皮素的生物合成通常由 III 型聚酮合酶 (PKS) 催化,使用一个对香豆酰辅酶 A 和三个丙二酰辅酶 A 分子作为底物。在这里,我们报道了一种用于柚皮素形成的真菌非核糖体肽合成酶-聚酮合酶(NRPS-PKS)杂合FnsA。同位素标记前体的喂养实验表明,FnsA 不仅接受对香豆酸 ( p -CA),还接受对羟基苯甲酸 ( p -HBA) 作为起始单元,并分别具有三个或四个丙二酰辅酶 A 分子用于延伸。体外实验和MS/MS分析证明p -CA和p -HBA首先被FnsA的腺苷酸化结构域激活。系统发育分析表明,FnsA 的 PKS 部分与 I 型 PKS 具有高度的序列同源性。在fnsA的参与下重构酵母中的生物合成途径为生产异鼠李素和金合欢素等黄酮类化合物提供了另一种方法。
Tandem Enzymatic Oxygenations in Biosynthesis of Epoxyquinone Pharmacophore of Manumycin-type Metabolites
作者:Zhe Rui、Moriah Sandy、Brian Jung、Wenjun Zhang
DOI:10.1016/j.chembiol.2013.05.006
日期:2013.7
Many natural products contain epoxyquinone pharmacophore with unknown biosynthetic mechanisms. Recent genetic analysis of the asukamycin biosynthetic gene cluster proposed enzyme candidates related to epoxyquinone formation for manumycin-type metabolites. Our biochemical studies reveal that 3-amino-4-hydroxyl benzoic acid (3,4-AHBA) precursor is activated and loaded on aryl carrier protein (AsuC12) by ATP-dependent adenylase (AsuA2). AsuE1 and AsuE3, both single-component flavin-dependent monooxygenases, catalyze the exquisite regio- and enantiospecific postpolyketide synthase (PKS) assembly oxygenations. AsuE1 installs a hydroxyl group on the 3,4-AHB ring to form a 4-hydroxyquinone moiety, which is epoxidized by AsuE3 to yield the epoxyquinone functionality. Despite being a single-component monooxygenase, AsuE1 activity is elicited by AsuE2, a pathway-specific flavin reductase. We further demonstrate that the epoxyquinone moiety is critical for anti-MRSA activity by analyzing the bioactivity of various manumycin-type metabolites produced through mutasynthesis.
A fungal NRPS-PKS enzyme catalyses the formation of the flavonoid naringenin
acid (p-HBA) as starter units, with three or four malonyl-CoA molecules for elongation, respectively. In vitro assays and MS/MS analysis prove that both p-CA and p-HBA are firstly activated by the adenylation domain of FnsA. Phylogenetic analysis reveals that the PKS portion of FnsA shares high sequence homology with type I PKSs. Refactoring the biosynthetic pathway in yeast with the involvement of
植物和细菌中类黄酮柚皮素的生物合成通常由 III 型聚酮合酶 (PKS) 催化,使用一个对香豆酰辅酶 A 和三个丙二酰辅酶 A 分子作为底物。在这里,我们报道了一种用于柚皮素形成的真菌非核糖体肽合成酶-聚酮合酶(NRPS-PKS)杂合FnsA。同位素标记前体的喂养实验表明,FnsA 不仅接受对香豆酸 ( p -CA),还接受对羟基苯甲酸 ( p -HBA) 作为起始单元,并分别具有三个或四个丙二酰辅酶 A 分子用于延伸。体外实验和MS/MS分析证明p -CA和p -HBA首先被FnsA的腺苷酸化结构域激活。系统发育分析表明,FnsA 的 PKS 部分与 I 型 PKS 具有高度的序列同源性。在fnsA的参与下重构酵母中的生物合成途径为生产异鼠李素和金合欢素等黄酮类化合物提供了另一种方法。