Evidence map›Paper›PMID 26976571›Full record

ArticleProceedings of the National Academy of Sciences of the United States of America2016

Aurone synthase is a catechol oxidase with hydroxylase activity and provides insights into the mechanism of plant polyphenol oxidases.

Christian Molitor, Stephan Gerhard Mauracher, Annette Rompel

Abstract read
In one paragraph

Article in Proceedings of the National Academy of Sciences of the United States of America, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 63 papers.

0numbers the graph read from it
0cells of the map it votes in
63citing papers in PubMed
7.8field-weighted citation impact, top 2% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

63 citing papers in PubMed, 135 citations in OpenAlex.

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  18. Genome-Wide Analysis of the Polyphenol Oxidase Gene Family inAntioxidants (Basel, Switzerland) · 2023
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3 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors at 1 institution in 1 country.

Christian MolitorInstitut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, 1090 Vienna, Austria.
Stephan Gerhard MauracherInstitut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, 1090 Vienna, Austria.
Annette RompelInstitut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, 1090 Vienna, Austria annette.rompel@univie.ac.at.ORCID http://orcid.org/0000-0002-5919-0553
University of Vienna · AT

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Tyrosinases and catechol oxidases belong to the family of polyphenol oxidases (PPOs). Tyrosinases catalyze theo-hydroxylation and oxidation of phenolic compounds, whereas catechol oxidases were so far defined to lack the hydroxylation activity and catalyze solely the oxidation of o-diphenolic compounds. Aurone synthase from Coreopsis grandiflora (AUS1) is a specialized plant PPO involved in the anabolic pathway of aurones. We present, to our knowledge, the first crystal structures of a latent plant PPO, its mature active and inactive form, caused by a sulfation of a copper binding histidine. Analysis of the latent proenzyme's interface between the shielding C-terminal domain and the main core provides insights into its activation mechanisms. As AUS1 did not accept common tyrosinase substrates (tyrosine and tyramine), the enzyme is classified as a catechol oxidase. However, AUS1 showed hydroxylase activity toward its natural substrate (isoliquiritigenin), revealing that the hydroxylase activity is not correlated with the acceptance of common tyrosinase substrates. Therefore, we propose that the hydroxylase reaction is a general functionality of PPOs. Molecular dynamics simulations of docked substrate-enzyme complexes were performed, and a key residue was identified that influences the plant PPO's acceptance or rejection of tyramine. Based on the evidenced hydroxylase activity and the interactions of specific residues with the substrates during the molecular dynamics simulations, a novel catalytic reaction mechanism for plant PPOs is proposed. The presented results strongly suggest that the physiological role of plant catechol oxidases were previously underestimated, as they might hydroxylate their--so far unknown--natural substrates in vivo.

Indexed as

Amino Acid SequenceBenzofuransBinding SitesCatalytic DomainCatechol OxidaseChalconesCopperCoreopsisModels, MolecularMolecular Dynamics SimulationMolecular Sequence DataPlant ProteinsProtein ConformationSubstrate SpecificityTyramineauroneBenzofuransbuteinCatechol OxidaseChalconesCopperisoliquiritigeninPlant ProteinsTyraminecatechol oxidasecrystal structuremechanismtype III copper proteintyrosinase

Identifiers

PMID26976571
PMCPMC4822611
OpenAlexW2300407673

What OpenQuestion holds

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Read underepoch 390

Registered trials

None linked

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.