Dataset Information

Moonlighting Metals: Insights into Regulation of Cyclization Pathways in Fungal ?(6) -Protoilludene Sesquiterpene Synthases.

ABSTRACT: Fungal 1,11 cyclizing sesquiterpene synthases are product specific under typical reaction conditions. However, in vivo expression of certain ?(6)-protoilludene synthases results in dual 1,11 and 1,10 cyclization. To determine the factors regulating this mechanistic variation, in-depth in vitro characterization of ?(6)-protoilludene synthases was conducted. Divalent metal ions determine cyclization specificity and this product variability. Promiscuity in metal binding is mediated by secondary metal-binding sites away from the conserved D(D/E)XX(D/E) motif in sesquiterpene synthases. Phylogenetic analysis revealed a divergent evolution of Basidiomycota trans-humulyl cation producing sesquiterpene synthases, results that indicate a wider diversity in function than previously predicted. This study provides key insights into the function and evolution of 1,11 cyclizing fungal sesquiterpene synthases.

SUBMITTER: Quin MB

PROVIDER: S-EPMC4742524 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Moonlighting Metals: Insights into Regulation of Cyclization Pathways in Fungal Δ(6) -Protoilludene Sesquiterpene Synthases.

Quin Maureen B MB Michel Stephen N SN Schmidt-Dannert Claudia C

Chembiochem : a European journal of chemical biology 20150901 15

Fungal 1,11 cyclizing sesquiterpene synthases are product specific under typical reaction conditions. However, in vivo expression of certain Δ(6)-protoilludene synthases results in dual 1,11 and 1,10 cyclization. To determine the factors regulating this mechanistic variation, in-depth in vitro characterization of Δ(6)-protoilludene synthases was conducted. Divalent metal ions determine cyclization specificity and this product variability. Promiscuity in metal binding is mediated by secondary met ...[more]

PMID: 26239156

Similar Datasets

Project description:BackgroundSesquiterpene lactones are characteristic metabolites of Asteraceae (or Compositae) which often display potent bioactivities and are sequestered in specialized organs such as laticifers, resin ducts, and trichomes. For characterization of sunflower sesquiterpene synthases we employed a simple method to isolate pure trichomes from anther appendages which facilitated the identification of these genes and investigation of their enzymatic functions and expression patterns during trichome development.ResultsGlandular trichomes of sunflower (Helianthus annuus L.) were isolated, and their RNA was extracted to investigate the initial steps of sesquiterpene lactone biosynthesis. Reverse transcription-PCR experiments led to the identification of three sesquiterpene synthases. By combination of in vitro and in vivo characterization of sesquiterpene synthase gene products in Escherichia coli and Saccharomyces cerevisiae, respectively, two enzymes were identified as germacrene A synthases, the key enzymes of sesquiterpene lactone biosynthesis. Due to the very low in vitro activity, the third enzyme was expressed in vivo in yeast as a thioredoxin-fusion protein for functional characterization. In in vivo assays, it was identified as a multiproduct enzyme with the volatile sesquiterpene hydrocarbon delta-cadinene as one of the two main products with alpha-muuorlene, beta-caryophyllene, alpha-humulene and alpha-copaene as minor products. The second main compound remained unidentified. For expression studies, glandular trichomes from the anther appendages of sunflower florets were isolated in particular developmental stages from the pre- to the post-secretory phase. All three sesquiterpene synthases were solely upregulated during the biosynthetically active stages of the trichomes. Expression in different aerial plant parts coincided with occurrence and maturity of trichomes. Young roots with root hairs showed expression of the sesquiterpene synthase genes as well.ConclusionThis study functionally identified sesquiterpene synthase genes predominantly expressed in sunflower trichomes. Evidence for the transcriptional regulation of sesquiterpene synthase genes in trichome cells suggest a potential use for these specialized cells for the identification of further genes involved in the biosynthesis, transport, and regulation of sesquiterpene lactones.

Dataset Information

Moonlighting Metals: Insights into Regulation of Cyclization Pathways in Fungal ?(6) -Protoilludene Sesquiterpene Synthases.

Publications

Moonlighting Metals: Insights into Regulation of Cyclization Pathways in Fungal Δ(6) -Protoilludene Sesquiterpene Synthases.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure