Characterization of the cytochrome P450 monooxygenase genes (P450ome) from the carotenogenic yeast Xanthophyllomyces dendrorhous

Pamela Córdova,Víctor Cifuentes,Jennifer Alcaíno,David R. Nelson,María-Soledad Gutiérrez,Ana-María Gonzalez,Marcelo Baeza

doi:10.1186/s12864-017-3942-9

Pamela Córdova, Víctor Cifuentes + Show 5 more

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https://doi.org/10.1186/s12864-017-3942-9

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Abstract

BackgroundThe cytochromes P450 (P450s) are a large superfamily of heme-containing monooxygenases involved in the oxidative metabolism of an enormous diversity of substrates. These enzymes require electrons for their activity, and the electrons are supplied by NAD(P)H through a P450 electron donor system, which is generally a cytochrome P450 reductase (CPR). The yeast Xanthophyllomyces dendrorhous has evolved an exclusive P450-CPR system that specializes in the synthesis of astaxanthin, a carotenoid with commercial potential. For this reason, the aim of this work was to identify and characterize other potential P450 genes in the genome of this yeast using a bioinformatic approach.ResultsThirteen potential P450-encoding genes were identified, and the analysis of their deduced proteins allowed them to be classified in ten different families: CYP51, CYP61, CYP5139 (with three members), CYP549A, CYP5491, CYP5492 (with two members), CYP5493, CYP53, CYP5494 and CYP5495. Structural analyses of the X. dendrorhous P450 proteins showed that all of them have a predicted transmembrane region at their N-terminus and have the conserved domains characteristic of the P450s, including the heme-binding region (FxxGxRxCxG); the PER domain, with the characteristic signature for fungi (PxRW); the ExxR motif in the K-helix region and the oxygen-binding domain (OBD) (AGxDTT); also, the characteristic secondary structure elements of all the P450 proteins were identified. The possible functions of these P450s include primary, secondary and xenobiotic metabolism reactions such as sterol biosynthesis, carotenoid synthesis and aromatic compound degradation.ConclusionsThe carotenogenic yeast X. dendrorhous has thirteen P450-encoding genes having potential functions in primary, secondary and xenobiotic metabolism reactions, including some genes of great interest for fatty acid hydroxylation and aromatic compound degradation. These findings established a basis for future studies about the role of P450s in the carotenogenic yeast X. dendrorhous and their potential biotechnological applications.

Highlights

The cytochromes P450 (P450s) are a large superfamily of heme-containing monooxygenases involved in the oxidative metabolism of an enormous diversity of substrates
Identification and structural analysis of X. dendrorhous P450-encoding genes Regarding the P450 genes, the cytochrome P450 homepage website built by Dr David Nelson has been available since 1995 [13], and in addition, a fungal specialized cytochrome P450 database has been available online since 2008 [5]
The X. dendrorhous P450ome would be one of the largest found in yeasts, since previous studies have shown that most yeasts have fewer than ten cytochrome P450s, with a few exceptions such as Candida albicans

Summary

Introduction

The cytochromes P450 (P450s) are a large superfamily of heme-containing monooxygenases involved in the oxidative metabolism of an enormous diversity of substrates. Cytochrome P450 enzymes (P450s or CYPs) constitute a large superfamily of heme containing monooxygenases widely distributed in different organisms from all the domains of life, including animals, plants, fungi and prokaryotes [1] These enzymes catalyze regio- and stereospecific conversions involved in the oxidative metabolism of a wide range of exogenous and endogenous substrates [2]. They are involved in the biosynthesis of many physiologically important compounds such as sterols, steroid hormones, fatty acids and vitamins [3] They participate in the biosynthesis of a vast array of secondary metabolites in plants, insects and fungi [4], providing them with adaptive advantages for the colonization of specific ecological and/or nutritional niches [5]. The typical reaction catalyzed by these enzymes is: RH + O2 + 2e− + 2H+ → ROH + H2O, where the electrons are transferred from NAD(P)H to P450s by an electron donor [7]

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