BRENDA - Enzyme Database

Contribution of two zeta-carotene desaturases to the poly-cis desaturation pathway in the cyanobacterium Nostoc PCC 7120

Breitenbach, J.; Bruns, M.; Sandmann, G.; Arch. Microbiol. 195, 491-498 (2013)

Data extracted from this reference:

Cloned(Commentary)
EC Number
Commentary
Organism
1.3.5.6
gene crtQa, expressionin Escherichia coli, gene crtQb, expression of CrtQB in Escherichia coli strain JM101
Nostoc sp.
Natural Substrates/ Products (Substrates)
EC Number
Natural Substrates
Organism
Commentary (Nat. Sub.)
Natural Products
Commentary (Nat. Pro.)
Organism (Nat. Pro.)
Reversibility
1.3.5.6
7,9,9'-tricis-neurosporene + a quinone
Nostoc sp.
catalyzed by zeta-carotene desaturase CrtQa, very poorly by CrtQb
7,9,7',9'-tetracis-lycopene + a quinol
-
-
?
1.3.5.6
9,9'-dicis-zeta-carotene + a quinone
Nostoc sp.
catalyzed by zeta-carotene desaturases CrtQa and CrtQb
7,9,9'-tricis-neurosporene + a quinol
-
-
?
1.3.5.6
additional information
Nostoc sp.
strain PCC 7120 contains two completely unrelated zeta-carotene desaturases CrtQa and CrtQb, which differ in their preferred utilization of zeta-carotene Z isomers. CrtQa con­verts zeta-carotene isomers that are poorly metabolized by CrtQb and CrtQa still possesses the Z to E isomerase function of the ancestral desaturase CrtI. CrtQb is an enzyme with one molecule of tightly bound FAD and acts as a dehydrogenase transferring hydrogen to oxidized plastoquinone. CrtQb yields only trace amounts of 7,9-Z neurosporene and 7,9,7',9'-Z lycopene
?
-
-
-
Organism
EC Number
Organism
Primary Accession No. (UniProt)
Commentary
Textmining
1.3.5.6
Nostoc sp.
-
contains two completely unrelated zeta-carotene desaturases CrtQa and CrtQb, encoded by genes crtQa and crtQb
-
Substrates and Products (Substrate)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
1.3.5.6
7,9,9'-tricis-neurosporene + a quinone
catalyzed by zeta-carotene desaturase CrtQa, very poorly by CrtQb
724142
Nostoc sp.
7,9,7',9'-tetracis-lycopene + a quinol
-
-
-
?
1.3.5.6
9,9'-dicis-zeta-carotene + a quinone
catalyzed by zeta-carotene desaturases CrtQa and CrtQb
724142
Nostoc sp.
7,9,9'-tricis-neurosporene + a quinol
-
-
-
?
1.3.5.6
additional information
strain PCC 7120 contains two completely unrelated zeta-carotene desaturases CrtQa and CrtQb, which differ in their preferred utilization of zeta-carotene Z isomers. CrtQa con­verts zeta-carotene isomers that are poorly metabolized by CrtQb and CrtQa still possesses the Z to E isomerase function of the ancestral desaturase CrtI. CrtQb is an enzyme with one molecule of tightly bound FAD and acts as a dehydrogenase transferring hydrogen to oxidized plastoquinone. CrtQb yields only trace amounts of 7,9-Z neurosporene and 7,9,7',9'-Z lycopene
724142
Nostoc sp.
?
-
-
-
-
1.3.5.6
additional information
zeta-carotene desaturase CrtQb converts (9Z)-zeta-carotene efficiently into (7Z,9Z)-neurosporene but stops at this stage without substantial lycopene formation. (all-E)-zeta-carotene cannot be converted by CrtQb. Similarly to (9Z)-zeta-carotene, the (all-E)-isomer is efficiently converted by CrtQa, substrate specificities, overview
724142
Nostoc sp.
?
-
-
-
-
Cofactor
EC Number
Cofactor
Commentary
Organism
Structure
1.3.5.6
FAD
tightly bound to zeta-carotene desaturase CrtQb
Nostoc sp.
Cloned(Commentary) (protein specific)
EC Number
Commentary
Organism
1.3.5.6
gene crtQa, expressionin Escherichia coli, gene crtQb, expression of CrtQB in Escherichia coli strain JM101
Nostoc sp.
Cofactor (protein specific)
EC Number
Cofactor
Commentary
Organism
Structure
1.3.5.6
FAD
tightly bound to zeta-carotene desaturase CrtQb
Nostoc sp.
Natural Substrates/ Products (Substrates) (protein specific)
EC Number
Natural Substrates
Organism
Commentary (Nat. Sub.)
Natural Products
Commentary (Nat. Pro.)
Organism (Nat. Pro.)
Reversibility
1.3.5.6
7,9,9'-tricis-neurosporene + a quinone
Nostoc sp.
catalyzed by zeta-carotene desaturase CrtQa, very poorly by CrtQb
7,9,7',9'-tetracis-lycopene + a quinol
-
-
?
1.3.5.6
9,9'-dicis-zeta-carotene + a quinone
Nostoc sp.
catalyzed by zeta-carotene desaturases CrtQa and CrtQb
7,9,9'-tricis-neurosporene + a quinol
-
-
?
1.3.5.6
additional information
Nostoc sp.
strain PCC 7120 contains two completely unrelated zeta-carotene desaturases CrtQa and CrtQb, which differ in their preferred utilization of zeta-carotene Z isomers. CrtQa con­verts zeta-carotene isomers that are poorly metabolized by CrtQb and CrtQa still possesses the Z to E isomerase function of the ancestral desaturase CrtI. CrtQb is an enzyme with one molecule of tightly bound FAD and acts as a dehydrogenase transferring hydrogen to oxidized plastoquinone. CrtQb yields only trace amounts of 7,9-Z neurosporene and 7,9,7',9'-Z lycopene
?
-
-
-
Substrates and Products (Substrate) (protein specific)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
1.3.5.6
7,9,9'-tricis-neurosporene + a quinone
catalyzed by zeta-carotene desaturase CrtQa, very poorly by CrtQb
724142
Nostoc sp.
7,9,7',9'-tetracis-lycopene + a quinol
-
-
-
?
1.3.5.6
9,9'-dicis-zeta-carotene + a quinone
catalyzed by zeta-carotene desaturases CrtQa and CrtQb
724142
Nostoc sp.
7,9,9'-tricis-neurosporene + a quinol
-
-
-
?
1.3.5.6
additional information
strain PCC 7120 contains two completely unrelated zeta-carotene desaturases CrtQa and CrtQb, which differ in their preferred utilization of zeta-carotene Z isomers. CrtQa con­verts zeta-carotene isomers that are poorly metabolized by CrtQb and CrtQa still possesses the Z to E isomerase function of the ancestral desaturase CrtI. CrtQb is an enzyme with one molecule of tightly bound FAD and acts as a dehydrogenase transferring hydrogen to oxidized plastoquinone. CrtQb yields only trace amounts of 7,9-Z neurosporene and 7,9,7',9'-Z lycopene
724142
Nostoc sp.
?
-
-
-
-
1.3.5.6
additional information
zeta-carotene desaturase CrtQb converts (9Z)-zeta-carotene efficiently into (7Z,9Z)-neurosporene but stops at this stage without substantial lycopene formation. (all-E)-zeta-carotene cannot be converted by CrtQb. Similarly to (9Z)-zeta-carotene, the (all-E)-isomer is efficiently converted by CrtQa, substrate specificities, overview
724142
Nostoc sp.
?
-
-
-
-