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MetaCyc Enzyme: carotenoid isomerase

Gene: CRTISO Accession Number: AT1G06820 (MetaCyc)

Species: Arabidopsis thaliana col

Summary:
Mutants affected in the Arabidopsis thaliana CRTISO gene accumulate acyclic, poly-cis-carotene precursors: prolycopene, 7,9,9'-cis-neurosporene and a mix of ζ-carotene isomers [Park02]. The accumulation of these compounds leads to a distinctive orange-yellow coloration of the cotyledons, in constrast with the yellow coloration of those of wild type. The accumulation of cis-carotenes rapidly disappears upon exposure to light. The protein responsible for this mutant phenotype was identified as a carotenoid isomerase. Its activity was confirmed by heterologous expression in Escherichia coli: extracts of mutant, dark-grown Arabidopsis mutants were co-incubated with recombinant CRTISO-expressing Escherichia coli extracts; the mixture was shown to consistently contain an increase in all-trans-lycopene, all-trans neurosporene and all-trans-ζ-carotene [Park02].

Unification Links: Entrez-gene:CRTISO , Entrez:NP_172167 , Mint:MINT-8067289 , PhylomeDB:Q9M9Y8 , Pride:Q9M9Y8 , Protein Model Portal:Q9M9Y8 , SMR:Q9M9Y8 , String:3702.AT1G06820.1-P , TAIR:AT1G06820 , UniProt:Q9M9Y8

Relationship Links: Entrez-Nucleotide:PART-OF:NM_100559 , InterPro:IN-FAMILY:IPR014101 , Panther:IN-FAMILY:PTHR10668:SF30 , Pfam:IN-FAMILY:PF00890

Gene-Reaction Schematic: ?

Gene-Reaction Schematic


Enzymatic reaction of: 7',9'-cis-lycopene isomerase (carotenoid isomerase)

EC Number: 5.2.1.-

7',9'-cis-lycopene <=> all-trans-lycopene

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Reversibility of this reaction is unspecified.

Summary:
Although this activity has not been identified through direct experimentation using 7',9'-cis-lycopene as a substrate, CRTISO is hypothesized to catalyze this reaction as suggested for a comparable enzyme in tomato [Isaacson04].


Enzymatic reaction of: 7,9,9'-cis-neurosporene isomerase (carotenoid isomerase)

EC Number: 5.2.1.-

7,9,9'-cis-neurosporene <=> 9'-cis-neurosporene

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Reversibility of this reaction is unspecified.

Summary:
Although this activity has not been identified through direct experimentation using 7,9,9'-cis-neurosporene as a substrate, CRTISO is hypothesized to catalyze this reaction as suggested for a comparable enzyme in tomato [Isaacson04].


Enzymatic reaction of: prolycopene isomerase (carotenoid isomerase)

EC Number: 5.2.1.13

prolycopene <=> all-trans-lycopene

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: superpathway of carotenoid biosynthesis , trans-lycopene biosynthesis II (plants)


References

Isaacson04: Isaacson T, Ohad I, Beyer P, Hirschberg J (2004). "Analysis in vitro of the enzyme CRTISO establishes a poly-cis-carotenoid biosynthesis pathway in plants." Plant Physiol 136(4);4246-55. PMID: 15557094

Park02: Park H, Kreunen SS, Cuttriss AJ, DellaPenna D, Pogson BJ (2002). "Identification of the carotenoid isomerase provides insight into carotenoid biosynthesis, prolamellar body formation, and photomorphogenesis." Plant Cell 14(2);321-32. PMID: 11884677


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Mon Jul 6, 2015, biocyc13.