Abstract

Apocarotenoids are carotenoid-derived compounds widespread in all major taxonomic groups, where they play important roles in different physiological processes. In addition, apocarotenoids include compounds with high economic value in food and cosmetics industries. Apocarotenoid biosynthesis starts with the action of carotenoid cleavage dioxygenases (CCDs), a family of non-heme iron enzymes that catalyze the oxidative cleavage of carbon–carbon double bonds in carotenoid backbones through a similar molecular mechanism, generating aldehyde or ketone groups in the cleaving ends. From the identification of the first CCD enzyme in plants, an increasing number of CCDs have been identified in many other species, including microorganisms, proving to be a ubiquitously distributed and evolutionarily conserved enzymatic family. This review focuses on CCDs from plants, algae, fungi, and bacteria, describing recent progress in their functions and regulatory mechanisms in relation to the different roles played by the apocarotenoids in these organisms.

Highlights

  • Carotenoids are a large group of terpenoid fat-soluble pigments widely distributed in nature

  • Apocarotenoid biosynthesis starts with the action of carotenoid cleavage dioxygenases (CCDs), a family of non-heme iron enzymes that catalyze the oxidative cleavage of carbon–carbon double bonds in carotenoid backbones through a similar molecular mechanism, generating aldehyde or ketone groups in the cleaving ends

  • This review focuses on CCDs from plants, algae, fungi, and bacteria, describing recent progress in their functions and regulatory mechanisms in relation to the different roles played by the apocarotenoids in these organisms

Read more

Summary

Introduction

Carotenoids are a large group of terpenoid fat-soluble pigments widely distributed in nature They are abundantly present in plants, where they are masked by the green color of chlorophyll, but they are responsible for the yellow, orange, or reddish colors of many fruits and flowers. Carotenoids exert important biological functions in most living organisms, usually related with their photoprotective and light-absorbing properties Their functions are especially relevant in plants, algae, cyanobacteria, and anoxygenic prototrophic bacteria [4,6,7], where they are indispensable in photosynthesis because of their light harvesting and protecting roles [8]. Apocarotenoids are usually the result of a biologically active process, resulting from the action of specific carotenoid cleavage dioxygenases (CCDs), frequently referred to as oxygenases (CCOs), a family of non-heme iron-type enzymes that cleave double bonds in the conjugated carbon chain of carotenoids [10]. The members of the nine-cis-epoxycarotenoid dioxygenases (NCED) subfamily responsible for the specific cleavage of 9-cis-epoxycarotenoids and involved in the production of abscisic acid (ABA) are not included in this review since it has been the subject of numerous studies and their activities and functions are well known [12,13,14,15,16,17,18]

Bacterial Carotenoid Oxygenases
Structural Studies
CCDs with Symmetrical Mode of Action
Carotenoid Oxygenases Cleaving at Different Positions
Fungal CCDs Involved in Trisporic Acid Production
Fungal CCDs Involved in Neurosporaxanthin Production
Plant CCDs
CCD1 and CCD2 Subfamilies
Mode of Action and Functional Implications
Mode of Action of CCD2
Structure of CCD1 and CCD2 Enzymes
Regulation of CCD1 and CCD2 Enzymes
The CCD4 Subfamily
Enzyme Structure and Functional Implications
Gene Family and Genomic Organization
CCD4 Activity
Expression Pattern in Plant Tissues
The CCD7 and CCD8 Subfamilies
CCDs in Algae
Findings
Conclusions
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.