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MetaCyc Enzyme: β-carotene 3-hydroxylase [multifunctional]

Gene: crtS Accession Number: G-9538 (MetaCyc)

Synonyms: asy

Species: Xanthophyllomyces dendrorhous

Summary:
The isolation of the gene crtS from the heterobasidiomycetous yeast Xanthophyllomyces dendrorhous was reported quasi-simultaneously in two publications [Ojima06, Alvarez06]. In both studies, the gene product was shown to be involved in the biosynthesis of astaxanthin. The protein is a cytochrome P450 with both β-carotenoid 3-hydroxylase and β-carotenoid 4-ketolase activity. The gene was expressed in the β-carotene-accumulating X. dendrorhous mutant PR-1-104 where substantial amounts of astaxanthin were detected along with adonirubin, 3-hydroxyechinenone and 3-hydroxy-4-ketotorulene [Ojima06]. Moreover, the gene was heterologously expressed in the fungus Mucor circinelloides where it was shown to increase the production of β-cryptoxanthin and zeaxanthin [Alvarez06], further demonstrating its involvement in 3-hydroxylation of β-carotenoids. This result is however in contrast with that published in [Ojima06] where the authors suggest that both activities are inseparable based on the observation that X. dendrorhous strains producing zeaxanthin and β-cryptoxanthin, in which the crtS gene was expressed, did not produce astaxanthin.

Molecular Weight of Polypeptide: 62.63 kD (from nucleotide sequence)

Unification Links: Entrez:ABB16282 , Entrez:CAC16261 , UniProt:Q3HR17

Relationship Links: Entrez-Nucleotide:PART-OF:AX034665 , Entrez-Nucleotide:PART-OF:DQ201828 , InterPro:IN-FAMILY:IPR001128 , InterPro:IN-FAMILY:IPR002403 , Pfam:IN-FAMILY:PF00067 , Prints:IN-FAMILY:PR00385 , Prints:IN-FAMILY:PR00465

Gene-Reaction Schematic: ?


Enzymatic reaction of: β-ring carotenoid 4-ketolase

EC Number: 1.14.99.-

3-hydroxyechinenone + a reduced electron acceptor + oxygen <=> adonirubin + an oxidized electron acceptor + H2O + 2 H+

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.

The reaction is physiologically favored in the direction shown.

In Pathways: astaxanthin biosynthesis


Enzymatic reaction of: β-ring carotenoid 3-hydroxylase

EC Number: 1.14.99.-

echinenone + a reduced electron acceptor + oxygen <=> 3-hydroxyechinenone + an oxidized electron acceptor + H2O

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.

The reaction is physiologically favored in the direction shown.

In Pathways: astaxanthin biosynthesis


Enzymatic reaction of: β-ring carotenoid 3-hydroxylase

EC Number: 1.14.99.-

4-ketotorulene + a reduced electron acceptor + oxygen <=> 3-hydroxy-4-ketotorulene + an oxidized electron acceptor + H2O

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.

The reaction is physiologically favored in the direction shown.


Enzymatic reaction of: β-ring carotenoid 4-ketolase

EC Number: 1.14.99.-

torulene + a reduced electron acceptor + oxygen <=> 4-ketotorulene + an oxidized electron acceptor + H2O + 2 H+

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.

The reaction is physiologically favored in the direction shown.


Enzymatic reaction of: β-ring carotenoid 3-hydroxylase

β-cryptoxanthin + NADH + oxygen + H+ <=> zeaxanthin + NAD+ + H2O

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.

The reaction is favored in the direction shown.

In Pathways: superpathway of carotenoid biosynthesis , astaxanthin biosynthesis , zeaxanthin biosynthesis


Enzymatic reaction of: β-carotene 3-hydroxylase

all-trans-β-carotene + NADH + oxygen + H+ <=> β-cryptoxanthin + NAD+ + H2O

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.

The reaction is favored in the direction shown.

In Pathways: superpathway of carotenoid biosynthesis , astaxanthin biosynthesis , zeaxanthin biosynthesis


Enzymatic reaction of: β-ring carotenoid 3-hydroxylase

EC Number: 1.14.99.-

adonirubin + a reduced electron acceptor + oxygen <=> 3S,3'S-astaxanthin + an oxidized electron acceptor + H2O

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.

The reaction is physiologically favored in the direction shown.

In Pathways: astaxanthin biosynthesis


Enzymatic reaction of: β-ring carotenoid 3-hydroxylase

EC Number: 1.14.99.-

canthaxanthin + a reduced electron acceptor + oxygen <=> adonirubin + an oxidized electron acceptor + H2O

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.

The reaction is physiologically favored in the direction shown.

In Pathways: astaxanthin biosynthesis


Enzymatic reaction of: β-ring carotenoid 4-ketolase

EC Number: 1.14.99.-

echinenone + a reduced electron acceptor + oxygen <=> canthaxanthin + an oxidized electron acceptor + H2O + 2 H+

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.

The reaction is physiologically favored in the direction shown.

In Pathways: astaxanthin biosynthesis


Enzymatic reaction of: β-carotene 4-ketolase

EC Number: 1.14.99.-

all-trans-β-carotene + a reduced electron acceptor + oxygen <=> echinenone + an oxidized electron acceptor + H2O + 2 H+

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.

The reaction is physiologically favored in the direction shown.

In Pathways: astaxanthin biosynthesis


References

Alvarez06: Alvarez V, Rodriguez-Saiz M, de la Fuente JL, Gudina EJ, Godio RP, Martin JF, Barredo JL (2006). "The crtS gene of Xanthophyllomyces dendrorhous encodes a novel cytochrome-P450 hydroxylase involved in the conversion of beta-carotene into astaxanthin and other xanthophylls." Fungal Genet Biol 43(4);261-72. PMID: 16455271

Ojima06: Ojima K, Breitenbach J, Visser H, Setoguchi Y, Tabata K, Hoshino T, van den Berg J, Sandmann G (2006). "Cloning of the astaxanthin synthase gene from Xanthophyllomyces dendrorhous (Phaffia rhodozyma) and its assignment as a beta-carotene 3-hydroxylase/4-ketolase." Mol Genet Genomics 275(2);148-58. PMID: 16416328


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 18.5 on Mon Mar 2, 2015, BIOCYC13A.