Metabolism of cyclic carotenoids: a model for the alteration of this biosynthetic pathway in Capsicum annuum chromoplasts

Abstract

The biosynthetic pathway of cyclic carotenoid is known to be quantitatively and qualitatively different in the non-green plastids of Capsicum annuum fruits compared with chloroplasts. Here, the cloning is described of a novel cDNA from this organism, which encodes an enzyme catalyzing the cyclization of lycopene to beta-carotene when expressed in Escherichia coli. The corresponding gene is constitutively expressed during fruit development. Significant amino acid sequence identity was observed between this enzyme and capsanthin/capsorubin synthase which is involved in the synthesis of the species-specific red carotenoids of C. annuum fruits. The latter enzyme was found also to possess a lycopene beta-cyclase activity when expressed in E. coli. A model is proposed for the origin of the capsanthin/capsorubin synthase gene and the role of this enzyme, together with the newly cloned lycopene cyclase, in the specific re-channeling of linear carotenoids into beta-cyclic carotenoids in C. annuum ripening fruits.

The Carotenoid 7, 8‐Dihydro‐ψ end Group can be Cyclized by the Lycopene Cyclases from the Bacterium Erwinia Uredovora and the Higher Plant Capsicum Annuum

“…The corresponding enzyme of Cupsicurn (LCY) showed significant amino acid similarity to the cyanobacterial lycopene cyclase [13]. Between lycopene cyclases of the bacterial type and the plant type, partial but significant amino acid similarity was observed [13]. Therefore, a similar substrate specificity for prokaryotic and eukaryotic lycopene cyclases should be expected.…”

Genome sequence of the hot pepper provides insights into the evolution of pungency in Capsicum species

“…The major pigments in pepper fruits are capsanthin and capsorubin, which are pepper-specific carotenoids synthesized by capsanthincapsorubin synthase (CCS) 54 . CCS exhibits lycopene β-cyclase activity 54 and has an orthologous relationship with chromoplast-specific lycopene β-cyclase (CYC-B) 55 , which exhibits ethylene-dependent repression 44 during tomato ripening.…”

“…CCS exhibits lycopene β-cyclase activity 54 and has an orthologous relationship with chromoplast-specific lycopene β-cyclase (CYC-B) 55 , which exhibits ethylene-dependent repression 44 during tomato ripening. CCS expression was extremely high during pepper ripening (Fig.…”

Tissue differential expression of lycopene β-cyclase gene in papaya

“…In capsicum peppers, the enzyme capsanthin-capsorubin synthase (CCS) converts violoxanthin and antheraxanthin to capsanthin and capsorubin, which give red color to the fruits. In addition, CCS also has some LCY-B activity [12,18,24,25]. In tomato, a second lycopene b-cyclase specific to the chromoplast has been identified [26] and named CYC-B [8].…”