Evidence map›Paper›PMID 27406087›Full record

ArticlePlant cell reports2016

Ectopic expression and functional characterization of type III polyketide synthase mutants from Emblica officinalis Gaertn.

Girija Aiswarya, Vijayanathan Mallika, Luis A J Mur, Eppurathu Vasudevan Soniya

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Article in Plant cell reports, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.3field-weighted citation impact, top 31% of its field
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3 · Its place in the literature

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3 citing papers in PubMed, 8 citations in OpenAlex.

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4 · The record

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5 · Who and what money

Authors and funding

4 authors at 2 institutions in 2 countries.

Girija AiswaryaPlant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, 695014, India.
Vijayanathan MallikaPlant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, 695014, India.
Luis A J MurInstitute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, UK. lum@aber.ac.uk.
Eppurathu Vasudevan SoniyaPlant Molecular Biology Division, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, 695014, India. evsoniya@rgcb.res.in.
Rajiv Gandhi Centre for Biotechnology · INAberystwyth University · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

key messageFunctional characterization and ectopic expression studies of chalcone synthase mutants implicate the role of phenylalanine in tailoring the substrate specificity of type III polyketide synthase. Chalcone synthase (CHS) is a plant-specific type III polyketide synthase that catalyzes the synthesis of flavonoids. Native CHS enzyme does not possess any functional activity on N-methylanthraniloyl-CoA, which is the substrate for acridione/quinolone alkaloid biosynthesis. Here, we report the functional transformation of chalcone synthase protein from Emblica officinalis (EoCHS) to quinolone and acridone synthase (ACS) with single amino acid substitutions. A cDNA of 1173 bp encoding chalcone synthase was isolated from E. officinalis and mutants (F215S and F265V) were generated by site-directed mutagenesis. Molecular modeling studies of EoCHS did not show any active binding with N-methylanthraniloyl-CoA, but the mutants of EoCHS showed strong affinity to the same. As revealed by the modeling studies, functional analysis of CHS mutants showed that they could utilize p-coumaroyl-CoA as well as N-methylanthraniloyl-CoA as substrates and yield active products such as naringenin, 4-hydroxy 1-methyl 2(H) quinolone and 1,3-dihydroxy-n-methyl acridone. Exchange of a single amino acid in EoCHS (F215S and F265V) resulted in functionally active mutants that preferred N-methylanthraniloyl-CoA over p-coumaroyl-CoA. This can be attributed to the increase in the relative volume of active sites in mutants by mutation. Moreover, metabolomic and MS analyses of tobacco leaves transiently expressing mutant genes showed high levels of naringenin, acridones and quinolone derivatives compared to wild-type CHS. This is the first report demonstrating the functional activity of EoCHS mutants with N-methylanthraniloyl-CoA and these results indicate the role of phenylalanine in altering the substrate specificity and in the evolution of type III PKSs.

Indexed as

Ectopic Gene ExpressionAmino Acid SequenceAmino Acid SubstitutionChromatography, High Pressure LiquidComputer SimulationDNA, ComplementaryElectrophoresis, Polyacrylamide GelGene Expression Regulation, PlantGenome, PlantMetabolomicsModels, MolecularMutagenesis, Site-DirectedMutationNicotianaPhenylalaninePhyllanthus emblicaDNA, ComplementaryPhenylalaninePolyketide SynthasesChalcone synthaseEmblica officinalisIn vitro assayMetabolomicsSite-directed mutagenesis

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PMID27406087
OpenAlexW2466174970

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.