in Arabidopsis: A colorful pathway.
Putative biosynthetic pathway of carotenoids in cyanobacteria. The names of enzymes are according to the crtE, geranylgeranyl pyrophosphate synthase; crtB, phytoene synthase; crtP, phytoene desaturase; crtQ, zeta-carotene desaturase; crtL, lycopene beta cyclase, ; lycopene epsilon cyclase; cruA, the most like candidate for lycopene cyclase by comparison to CT0456 in the species lacking crtL. crtO/crtW, beta-carotene ketolase; crtR, beta-carotene hydroxylase.
Carotenoid biosynthesis in Arabidopsis: a colorful pathway
16. Misawa N, Satomi Y, Kondo K, Yam AY, Kajiwara S, Saito T, Ohtani T, Miki W. Structure and functional analysis of a marine bacterial carotenoid biosynthesis gene cluster and astaxanthin biosynthetic pathway proposed at the gene level. 1995;177:6575-6584
Presumed enzymes involved in the biosynthetic pathway of carotenoids among different cyanobacterial species. Some enzymes have been functionally identified, while others are just suggested by sequence homology. Database searches were carried out with the BLASTP program. (a) Putative carotenoid synthetic pathway diagram. The shading reflects correspondence to specific genes, numbers and colors are the same as in (b). (b) A list of major enzymes and proteins involved in cyanobacterial carotenoid biosynthesis. Presence or absence of putative orthologs in a given genome is indicated by '+' or '-', respectively. The gene IDs of putative othologous genes are listed in supplemental material.
Metabolic Pathway Data; Phenotypes; ..
Similarity search between query sequences and cyanobacterial genomes were performed by BLASTP program. The distribution of genes involved in carotenoid biosynthesis across 18 cyanobacterial genomes is summarized in Figure . We can see geranylgeranyl pyrophosphate synthase (crtE/GGPS) and phytoene synthase genes (crtB/pys) are widely distributed among all the species. The cyanobacteria share the same carotenoid biosynthetic pathway to lycopene except for 7421.
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Now whole-genome information is being generated for a number of cyanobacteria.16 cyanobacterial genomes have been fully sequenced and 2 in the draft format and more than 20 are in the process of being sequenced (; ).The complete genome sequences of cyanobacteria allowed us to obtain a comprehensive data set of genes encoding enzymes in the carotenoid biosynthetic pathway. Moreover, even if experimental studies have become possible to reconstruct the pathway on the basis of a prediction of the genes and its function from the complete genome sequence data. Genome-wide screening of genes based on the genome-sequencing project provided us a new and comprehensive insight into the cyanobacterial carotenoid biosynthetic pathway. In this article, emphasis is centered on the comparative analysis of cyanobacteria and shedding light on the diversity of the carotenoid biosynthesis pathway based on the information of genomes.
Carotenoid Biosynthesis (Zea mays) - WikiPathways
PSY regulates the beginning step of the carotenoid metabolic pathway and its expression significantly affects the amount of subsequently produced carotenoids. In genome, is a single gene located on chromosome 5, although many mRNA sequence entries have been registered. In tomato and rice, two and three have been molecularly characterized and they played different roles and expression profiles during plant development and tissues-specific function or seasonal variation (, ). Based on the gene structure and expression pattern of homologues in the clementine mandarin genome sequence, there are two loci for chloroplastic phytoene synthase and cytosolic squarene/phytoene synthase. The locus in the scaffold 6, which is mapped by marker on the linkage group 4 of the AGI map, is considered as a principal locus for carotenoid biosynthesis in citrus. The alternative locus comprises three tandem homologues without putative transit peptide, which are members of cytosolic squarene/phytoene synthases, and might not contributed to carotenoid biosynthesis. In addition, it was confirmed that four in the AG population have high identities with the past reported citrus and they were derived from the single locus in the scaffold 6 from the segregation analysis. Therefore, it is proposed that for carotenoid biosynthesis would be derived from a single locus with various sequence diversity working as multiallelism among citrus varieties.