Cyanobacteria uniquely contain a primitive water-soluble carotenoprotein, the orange carotenoid protein (OCP). Nearly all extant cyanobacterial genomes contain genes for the OCP or its homologs, implying an evolutionary constraint for cyanobacteria to conserve its function. Genes encoding the OCP and its two constituent structural domains, the N-terminal domain, helical carotenoid proteins (HCPs), and its C-terminal domain, are found in the most basal lineages of extant cyanobacteria. These three carotenoproteins exemplify the importance of the protein for carotenoid properties, including protein dynamics, in response to environmental changes in facilitating a photoresponse and energy quenching. Here, we review new structural insights for these carotenoproteins and situate the role of the protein in what is currently understood about their functions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.tibs.2024.04.010 | DOI Listing |
Plant Biotechnol J
January 2025
Department of Plant Breeding and Biotechnology, Centro IFAPA de Málaga, Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Málaga, Spain.
Carotenoids are a diverse group of pigments imparting red, orange, and yellow hues to many horticultural plants, also enhancing their nutritional properties and health benefits. In strawberry, the genetic and molecular mechanisms regulating the natural variation of fruit carotenoid composition remain largely unexplored. In this study, we use a population segregating in yellow/white flesh to detect a major quantitative trait locus (QTL), qYellow Flesh-4B, located on chromosome 4B and accounting for 82% of total phenotypic variation.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Max Planck Institute for Medical Research, Jahnstr. 29, Heidelberg 69120, Germany.
Orange carotenoid protein (OCP) is a photoactive protein that mediates photoprotection in cyanobacteria. OCP binds different ketocarotenoid chromophores such as echinenone (ECN), 3'- hydroxyechinenone (hECN), and canthaxanthin (CAN). In the dark, OCP is in an inactive orange form known as OCP; upon illumination, a red active state is formed, referred to as OCP, that can interact with the phycobilisome.
View Article and Find Full Text PDFPhotosynth Res
January 2025
Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.
The Orange Carotenoid Protein (OCP) is a unique water-soluble photoactive protein that plays a critical role in regulating the balance between light harvesting and photoprotective responses in cyanobacteria. The challenge in understanding OCP´s photoactivation mechanism stems from the heterogeneity of the initial configurations of its embedded ketocarotenoid, which in the dark-adapted state can form up to two hydrogen bonds to critical amino acids in the protein's C-terminal domain, and the extremely low quantum yield of primary photoproduct formation. While a series of experiments involving point mutations within these contacts helped us to identify these challenges, they did not resolve them.
View Article and Find Full Text PDFBMC Plant Biol
January 2025
Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.
Gloriosa L. possesses exceptional ornamental value, with its floral hues exhibiting a wide range of variations. In this study, we employed sophisticated colorimetry, Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS), and transcriptome sequencing to investigate the phenotypic expression of tepal colors, the composition of carotenoids and anthocyanins, and the differential gene expression in four Gloriosa varieties during their full bloom phase.
View Article and Find Full Text PDFBiochim Biophys Acta Bioenerg
January 2025
Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany. Electronic address:
In this study, the oligomerization pattern of apo- and holoforms of the Orange Carotenoid Protein (OCP) was examined under different conditions such as photoactivation state, concentration, and carotenoid embedment using analytical ultracentrifugation. Furthermore, studies were conducted on OCP constructs carrying point mutations of amino acid residues affecting OCP oligomerization. Our findings reveal that the concentration-dependent dimerization of dark-adapted OCP holoprotein from Synechocystis sp.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!