Alkylresorcylic acid synthesis by type III polyketide synthases from rice Oryza sativa

Matsuzawa, Miku; Katsuyama, Yoshihiko; Funa, Nobutaka; Horinouchi, Sueharu

doi:10.1016/j.phytochem.2010.02.012

Cited by 31 publications

(22 citation statements)

References 32 publications

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“…S1). Our conclusion was validated by a similar phylogenetic reconstruction , and by gene expression and enzyme activity analyses . Genome sequences of other plant species were similarly analyzed, and this revealed more novel ASCLs, including three from Populus , two from Sorghum , and one from Selaginella species (Fig.…”

Section: Resultssupporting

confidence: 69%

Hypericum perforatum hydroxyalkylpyrone synthase involved in sporopollenin biosynthesis – phylogeny, site‐directed mutagenesis, and expression in nonanther tissues

et al. 2014

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Anther-specific chalcone synthase-like enzyme (ASCL), an ancient plant type III polyketide synthase, is involved in the biosynthesis of sporopollenin, the stable biopolymer found in the exine layer of the wall of a spore or pollen grain. The gene encoding polyketide synthase 1 from Hypericum perforatum (HpPKS1) was previously shown to be expressed mainly in young flower buds, but also in leaves and other tissues at lower levels. Angiosperm ASCLs, identified by sequence and phylogenetic analyses, are divided into two sister clades, the Ala-clade and the Val-clade, and HpPKS1 belongs to the Ala-clade. Recombinant HpPKS1 produced triketide and, to a lesser extent, tetraketide alkylpyrones from medium-chain (C 6 ) to very long-chain (C 24 ) fatty acyl-CoA substrates. Like other ASCLs, HpPKS1 also preferred hydroxyl fatty acyl-CoA esters over the analogous unsubstituted fatty acyl-CoA esters. To study the structural basis of the substrate preference, mutants of Ala200 and Ala215 at the putative active site and Arg202 and Asp211 at the modeled acyl-binding tunnel were constructed. The A200T/A215Q mutant accepted decanoyl-CoA, a poor substrate for the wild-type enzyme, possibly because of active site constriction by bulkier substitutions. The substrate preference of the A215V and A200T/A215Q mutants shifted toward nonhydroxylated, medium-chain to long-chain fatty acyl-CoA substrates. The R202L/D211V double mutant was selective for acyl-CoA with chain lengths of C 16 -C 18 , and showed a diminished preference for the hydroxylated acyl-CoA substrates. Transient upregulation by abscisic acid and downregulation by jasmonic acid and wounding suggested that HpPKS1, and possibly other Ala-clade ASCLs, may be involved in the biosynthesis of minor cell wall components in nonanther tissues.

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Section: Resultssupporting

confidence: 69%

Hypericum perforatum hydroxyalkylpyrone synthase involved in sporopollenin biosynthesis – phylogeny, site‐directed mutagenesis, and expression in nonanther tissues

et al. 2014

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“…Trp-281 of ArsB is replaced by Gly in STS. In other plant alkylresorcylic acid synthases, Oryza sativa ARAS1 and ARAS2 (31), this aromatic residue is replaced by Met. Consequently, several amino acid variations and structural differences are observed between microbial and plant aldol condensation-catalyzing type III PKSs, indicating that different reaction mechanisms are employed.…”

Section: Discussionmentioning

confidence: 99%

Structural Basis for Cyclization Specificity of Two Azotobacter Type III Polyketide Synthases

Satou¹,

Miyanaga

Ozawa

et al. 2013

Journal of Biological Chemistry

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Background: Type III polyketide synthases (PKSs) show diverse cyclization specificity. Results: A single amino acid substitution in two Azotobacter type III PKSs reversed their cyclization specificity. Crystal structures were determined. Conclusion: The volume of the active site cavity is a crucial determinant of the cyclization specificity. Significance: An important insight into the cyclization specificity of type III PKSs was provided.

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“…Examples of plant metabolites formed by C2-C7 aldol condensation with carboxylate retention are the anacardic acids in cashew and gingko and stilbene carboxylates in Hydrangea species and liverworts (38,39). It is worth noting that a rice type III PKS synthesizes long-chain alkylresorcinolic acids without the need for a cyclase enzyme (40). Another indication that some plant polyketide pathways may require cyclases is the formation of α-pyrones when recombinant type III PKSs enzymes are assayed in vitro e.g., Hypericum perforatum octaketide synthase (41).…”

Section: Aromatic Prenyltransferasementioning

confidence: 99%

Identification of olivetolic acid cyclase from Cannabis sativa reveals a unique catalytic route to plant polyketides

Gagne

Stout²,

Liu³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

256

236

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Δ 9 -Tetrahydrocannabinol (THC) and other cannabinoids are responsible for the psychoactive and medicinal properties of Cannabis sativa L. (marijuana). The first intermediate in the cannabinoid biosynthetic pathway is proposed to be olivetolic acid (OA), an alkylresorcinolic acid that forms the polyketide nucleus of the cannabinoids. OA has been postulated to be synthesized by a type III polyketide synthase (PKS) enzyme, but so far type III PKSs from cannabis have been shown to produce catalytic byproducts instead of OA. We analyzed the transcriptome of glandular trichomes from female cannabis flowers, which are the primary site of cannabinoid biosynthesis, and searched for polyketide cyclase-like enzymes that could assist in OA cyclization. Here, we show that a type III PKS (tetraketide synthase) from cannabis trichomes requires the presence of a polyketide cyclase enzyme, olivetolic acid cyclase (OAC), which catalyzes a C2-C7 intramolecular aldol condensation with carboxylate retention to form OA. OAC is a dimeric α+β barrel (DABB) protein that is structurally similar to polyketide cyclases from Streptomyces species. OAC transcript is present at high levels in glandular trichomes, an expression profile that parallels other cannabinoid pathway enzymes. Our identification of OAC both clarifies the cannabinoid pathway and demonstrates unexpected evolutionary parallels between polyketide biosynthesis in plants and bacteria. In addition, the widespread occurrence of DABB proteins in plants suggests that polyketide cyclases may play an overlooked role in generating plant chemical diversity.natural products | phytocannabinoid | terpenophenolic | aldolase | ferredoxin-like

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Alkylresorcylic acid synthesis by type III polyketide synthases from rice Oryza sativa

Cited by 31 publications

References 32 publications

Hypericum perforatum hydroxyalkylpyrone synthase involved in sporopollenin biosynthesis – phylogeny, site‐directed mutagenesis, and expression in nonanther tissues

Hypericum perforatum hydroxyalkylpyrone synthase involved in sporopollenin biosynthesis – phylogeny, site‐directed mutagenesis, and expression in nonanther tissues

Structural Basis for Cyclization Specificity of Two Azotobacter Type III Polyketide Synthases

Identification of olivetolic acid cyclase from Cannabis sativa reveals a unique catalytic route to plant polyketides

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