| Entry |
|
| Name |
chlorophyllide-a oxygenase;
chlorophyllide a oxygenase;
chlorophyll-b synthase;
CAO
|
| Class |
Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With NADH or NADPH as one donor, and incorporation of one atom of oxygen into the other donor
 |
| Sysname |
chlorophyllide-a:oxygen 71-oxidoreductase
|
| Reaction(IUBMB) |
chlorophyllide a + 2 O2 + 2 NADPH + 2 H+ = chlorophyllide b + 3 H2O + NADP+ (overall reaction) [RN: R10080];
(1a) chlorophyllide a + O2 + NADPH + H+ = 71-hydroxychlorophyllide a + H2O + NADP+ [RN: R08203];
(1b) 71-hydroxychlorophyllide a + O2 + NADPH + H+ = chlorophyllide b + 2 H2O + NADP+ [RN: R08204]
|
| Reaction(KEGG) |
|
| Substrate |
|
| Product |
chlorophyllide b [CPD: C16541];
H2O [CPD: C00001];
NADP+ [CPD: C00006];
71-hydroxychlorophyllide a
|
| Comment |
Chlorophyll b is required for the assembly of stable light-harvesting complexes (LHCs) in the chloroplast of green algae, cyanobacteria and plants [2,3]. Contains a mononuclear iron centre [3]. The enzyme catalyses two successive hydroxylations at the 7-methyl group of chlorophyllide a. The second step yields the aldehyde hydrate, which loses H2O spontaneously to form chlorophyllide b [2]. Chlorophyll a and protochlorophyllide a are not substrates [2].
|
| History |
EC 1.14.13.122 created 2006 as EC 1.13.12.14, transferred 2011 to EC 1.14.13.122, modified 2011
|
| Pathway |
| Porphyrin and chlorophyll metabolism | | Metabolic pathways | | Biosynthesis of secondary metabolites |
|
| Orthology |
| chlorophyllide a oxygenase |
|
| Genes |
ATH: | | ALY: | | CRB: | | EUS: | | BRP: | | BNA: | | THJ: | | CIT: | | CIC: | | TCC: | | GRA: | | GHI: | | EGR: | | GMX: | | PVU: | | VRA: | | VAR: | | CCAJ: | | MTR: | | CAM: | | ADU: | | AIP: | | LJA: | | LANG: | | FVE: | | PPER: | | PMUM: | | MDM: | | PXB: | | ZJU: | | CSV: | | CMO: | | RCU: | | JCU: | | POP: | | VVI: | | SLY: | | SPEN: | | SOT: | | INI: | | SIND: | | BVG: | | NNU: | | OSA: | | DOSA: | | OBR: | | BDI: | | ATS: | | SBI: | | ZMA: | | SITA: | | PDA: | | EGU: | | MUS: | | ATR: | | SMO: | | PPP: | | CRE: | | VCN: | | OLU: | | OTA: | | BPG: | | MIS: | | MPP: | | CSL: | | CVR: | | APRO: | | ACAN: | | » show all
 |
| Reference |
|
| Authors |
Espineda CE, Linford AS, Devine D, Brusslan JA. |
| Title |
The AtCAO gene, encoding chlorophyll a oxygenase, is required for chlorophyll b synthesis in Arabidopsis thaliana. |
| Journal |
Proc. Natl. Acad. Sci. U. S. A. 96 (1999) 10507-11. |
| Sequence |
|
| Reference |
|
| Authors |
Oster U, Tanaka R, Tanaka A, Rudiger W. |
| Title |
Cloning and functional expression of the gene encoding the key enzyme for chlorophyll b biosynthesis (CAO) from Arabidopsis thaliana. |
| Journal |
Plant. J. 21 (2000) 305-10. |
| Sequence |
|
| Reference |
|
| Authors |
Eggink LL, LoBrutto R, Brune DC, Brusslan J, Yamasato A, Tanaka A, Hoober JK. |
| Title |
Synthesis of chlorophyll b: localization of chlorophyllide a oxygenase and discovery of a stable radical in the catalytic subunit. |
| Journal |
BMC. Plant. Biol. 4 (2004) 5. |
| Sequence |
|
| Reference |
|
| Authors |
Porra RJ, Schafer W, Cmiel E, Katheder I, Scheer H. |
| Title |
The derivation of the formyl-group oxygen of chlorophyll b in higher plants from molecular oxygen. Achievement of high enrichment of the 7-formyl-group oxygen from 18O2 in greening maize leaves. |
| Journal |
Eur. J. Biochem. 219 (1994) 671-9. |
| Other DBs |
ExplorEnz - The Enzyme Database: IUBMB Enzyme Nomenclature: ExPASy - ENZYME nomenclature database: BRENDA, the Enzyme Database: CAS: 216503-73-0 |
| LinkDB |
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