Dataset Information

Roles of the 2-Oxoglutarate-Dependent Dioxygenase Superfamily in the Flavonoid Pathway: A Review of the Functional Diversity of F3H, FNS I, FLS, and LDOX/ANS.

ABSTRACT: The 2-oxoglutarate-dependent dioxygenase (2-OGD) superfamily is one of the largest protein families in plants. The main oxidation reactions they catalyze in plants are hydroxylation, desaturation, demethylation, epimerization, and halogenation. Four members of the 2-OGD superfamily, i.e., flavonone 3β-hydroxylase (F3H), flavones synthase I (FNS I), flavonol synthase (FLS), and anthocyanidin synthase (ANS)/leucoanthocyanidin dioxygenase (LDOX), are present in the flavonoid pathway, catalyzing hydroxylation and desaturation reactions. In this review, we summarize the recent research progress on these proteins, from the discovery of their enzymatic activity, to their functional verification, to the analysis of the response they mediate in plants towards adversity. Substrate diversity analysis indicated that F3H, FNS Ⅰ, ANS/LDOX, and FLS perform their respective dominant functions in the flavonoid pathway, despite the presence of functional redundancy among them. The phylogenetic tree classified two types of FNS Ⅰ, one mainly performing FNS activity, and the other, a new type of FNS present in angiosperms, mainly involved in C-5 hydroxylation of SA. Additionally, a new class of LDOXs is highlighted, which can catalyze the conversion of (+)-catechin to cyanidin, further influencing the starter and extension unit composition of proanthocyanidins (PAs). The systematical description of the functional diversity and evolutionary relationship among these enzymes can facilitate the understanding of their impacts on plant metabolism. On the other hand, it provides molecular genetic evidence of the chemical evolution of flavonoids from lower to higher plants, promoting plant adaptation to harsh environments.

SUBMITTER: Wang Y

PROVIDER: S-EPMC8588099 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Roles of the 2-Oxoglutarate-Dependent Dioxygenase Superfamily in the Flavonoid Pathway: A Review of the Functional Diversity of F3H, FNS I, FLS, and LDOX/ANS.

Wang Yueyue Y Shi Yufeng Y Li Kaiyuan K Yang Dong D Liu Nana N Zhang Lingjie L Zhao Lei L Zhang Xinfu X Liu Yajun Y Gao Liping L Xia Tao T Wang Peiqiang P

Molecules (Basel, Switzerland) 20211108 21

The 2-oxoglutarate-dependent dioxygenase (2-OGD) superfamily is one of the largest protein families in plants. The main oxidation reactions they catalyze in plants are hydroxylation, desaturation, demethylation, epimerization, and halogenation. Four members of the 2-OGD superfamily, i.e., flavonone 3β-hydroxylase (F3H), flavones synthase I (FNS I), flavonol synthase (FLS), and anthocyanidin synthase (ANS)/leucoanthocyanidin dioxygenase (LDOX), are present in the flavonoid pathway, catalyzing hyd ...[more]

PMID: 34771153

Similar Datasets

Project description:BackgroundFlavonoids are necessary for plant growth and resistance to adversity and stress. They are also an essential nutrient for human diet and health. Among the metabolites produced in Cannabis sativa (C. sativa), phytocannabinoids have undergone extensive research on their structures, biosynthesis, and biological activities. Besides the phytocannabinoids, C. sativa is also rich in terpenes, alkaloids, and flavonoids, although little research has been conducted in this area.ResultsIn this study, we identified 11 classes of key enzyme-encoding genes, including 56 members involved in the flavonoid biosynthesis in C. sativa, from their physical characteristics to their expression patterns. We screened the potentially step-by-step enzymes catalyzing the precursor phenylalanine to the end flavonoids using a conjoin analysis of gene expression with metabolomics from different tissues and chemovars. Flavonol synthase (FLS), belonging to the 2-oxoglutarate-dependent dioxygenase (2-ODD) superfamily, catalyzes the dihydroflavonols to flavonols. In vitro recombinant protein activity analysis revealed that CsFLS2 and CsFLS3 had a dual function in converting naringenin (Nar) to dihydrokaempferol (DHK), as well as dihydroflavonols to flavonols with different substrate preferences. Meanwhile, we found that CsFLS2 produced apigenin (Api) in addition to DHK and kaempferol when Nar was used as the substrate, indicating that CsFLS2 has an evolutionary relationship with Cannabis flavone synthase I.ConclusionsOur study identified key enzyme-encoding genes involved in the biosynthesis of flavonoids in C. sativa and highlighted the key CsFLS genes that generate flavonols and their diversified functions in C. sativa flavonoid production. This study paves the way for reconstructing the entire pathway for C. sativa's flavonols and cannflavins production in heterologous systems or plant culture, and provides a theoretical foundation for discovering new cannabis-specific flavonoids.

Project description:BackgroundFlavonoids are plant specialised metabolites, which derive from phenylalanine and acetate metabolism. They possess a variety of beneficial characteristics for plants and humans. Several modification steps in the synthesis of tricyclic flavonoids cause for the amazing diversity of flavonoids in plants. The 2-oxoglutarate-dependent dioxygenases (2-ODDs) flavanone 3-hydroxylase (F3H, synonym FHT), flavonol synthase (FLS) and anthocyanidin synthase (ANS, synonym leucoanthocyanidin dioxygenase (LDOX)), catalyse oxidative modifications to the central C ring. They are highly similar and have been shown to catalyse, at least in part, each other's reactions. FLS and ANS have been identified as bifunctional enzymes in many species, including Arabidopsis thaliana, stressing the capability of plants to bypass missing or mutated reaction steps on the way to flavonoid production. However, little is known about such bypass reactions and the flavonoid composition of plants lacking all three central flavonoid 2-ODDs.ResultsTo address this issue, we generated a f3h/fls1/ans mutant, as well as the corresponding double mutants and investigated the flavonoid composition of this mutant collection. The f3h/fls1/ans mutant was further characterised at the genomic level by analysis of a nanopore DNA sequencing generated genome sequence assembly and at the transcriptomic level by RNA-Seq analysis. The mutant collection established, including the novel double mutants f3h/fls1 and f3h/ans, was used to validate and analyse the multifunctionalities of F3H, FLS1, and ANS in planta. Metabolite analyses revealed the accumulation of eriodictyol and additional glycosylated derivatives in mutants carrying the f3h mutant allele, resulting from the conversion of naringenin to eriodictyol by flavonoid 3'-hydroxylase (F3'H) activity.ConclusionsWe describe the in planta multifunctionality of the three central flavonoid 2-ODDs from A. thaliana and identify a bypass in the f3h/fls1/ans triple mutant that leads to the formation of eriodictyol derivatives. As (homo-)eriodictyols are known as bitter taste maskers, the annotated eriodictyol (derivatives) and in particular the observations made on their in planta production, could provide valuable insights for the creation of novel food supplements.

Project description:Pyrrolnitrin is a commonly used and clinically effective treatment for fungal infections and provides the structural basis for the more widely used fludioxinil. The pyrrolnitrin biosynthetic pathway consists of four chemical steps, the second of which is the rearrangement of 7-chloro-tryptophan by the enzyme PrnB, a reaction that is so far unprecedented in biochemistry. When expressed in Pseudomonas fluorescens, PrnB is red in color due to the fact that it contains 1 mol of heme b per mole of protein. The crystal structure unexpectedly establishes PrnB as a member of the heme-dependent dioxygenase superfamily with significant structural but not sequence homology to the two-domain indoleamine 2,3-dioxygenase enzyme (IDO). The heme-binding domain is also structurally similar to that of tryptophan 2,3-dioxygenase (TDO). Here we report the binary complex structures of PrnB with d- and l-tryptophan and d- and l-7-chloro-tryptophan. The structures identify a common hydrophobic pocket for the indole ring but exhibit unusual heme ligation and substrate binding when compared with that observed in the TDO crystal structures. Our solution studies support the heme ligation observed in the crystal structures. Purification of the hexahistidine-tagged PrnB yields homogeneous protein that only displays in vitro activity with 7-chloro-l-tryptophan after reactivation with crude extract from the host strain, suggesting that an as yet unknown cofactor is required for activity. Mutation of the proximal heme ligand results, not surprisingly, in inactive enzyme. Redox titrations show that PrnB displays a significantly different reduction potential to that of IDO or TDO, indicating possible differences in the PrnB catalytic cycle. This is confirmed by the absence of tryptophan dioxygenase activity in PrnB, although a stable oxyferrous adduct (which is the first intermediate in the TDO/IDO catalytic cycle) can be generated. We propose that PrnB shares a key catalytic step with TDO and IDO, generation of a tryptophan hydroperoxide intermediate, although this species suffers a different fate in PrnB, leading to the eventual formation of the product, monodechloroaminopyrrolnitrin.

Dataset Information

Roles of the 2-Oxoglutarate-Dependent Dioxygenase Superfamily in the Flavonoid Pathway: A Review of the Functional Diversity of F3H, FNS I, FLS, and LDOX/ANS.

Publications

Roles of the 2-Oxoglutarate-Dependent Dioxygenase Superfamily in the Flavonoid Pathway: A Review of the Functional Diversity of F3H, FNS I, FLS, and LDOX/ANS.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets