Information on EC 1.14.13.122 - chlorophyllide-a oxygenase

Word Map on EC 1.14.13.122
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Select one or more organisms in this record:
Show additional data
Do not include text mining results
Include (text mining) results (more...)
Include results (AMENDA + additional results, but less precise; more...)


The expected taxonomic range for this enzyme is: Bacteria, Eukaryota

EC NUMBER
COMMENTARY hide
1.14.13.122
-
RECOMMENDED NAME
GeneOntology No.
chlorophyllide-a oxygenase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
71-hydroxychlorophyllide a + O2 + NADPH + H+ = chlorophyllide b + 2 H2O + NADP+
show the reaction diagram
(1b)
-
-
-
chlorophyllide a + 2 O2 + 2 NADPH + 2 H+ = chlorophyllide b + 3 H2O + 2 NADP+
show the reaction diagram
chlorophyllide a + O2 + NADPH + H+ = 71-hydroxychlorophyllide a + H2O + NADP+
show the reaction diagram
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Biosynthesis of secondary metabolites
-
-
Metabolic pathways
-
-
Porphyrin and chlorophyll metabolism
-
-
chlorophyll metabolism
-
-
SYSTEMATIC NAME
IUBMB Comments
chlorophyllide-a:oxygen 7-oxidoreductase
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].
CAS REGISTRY NUMBER
COMMENTARY hide
216503-73-0
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
strain 5D
SwissProt
Manually annotated by BRENDA team
strain cw15
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
fragment containing the CAO gene
SwissProt
Manually annotated by BRENDA team
cultivars Tron, Bonus, and Donaria
UniProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
metabolism
-
the enzyme is responsible for chlorophyll b biosynthesis
physiological function
-
enzyme overexpression results in increased chlorophyll b synthesis and a decreased chlorophyll a/b ratio in low light-grown as well as high light-grown tobacco plants. This effect, however, is more pronounced in high light. Enzyme overexpression affects the chlorophyll biosynthetic flux by modulating the gene and protein expression of several other chlorophyll biosynthetic pathway enzymes (i.e. Mg-protoporphyrin IX:S-adenosyl-Met methyltransferase)
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
7-hydroxychlorophyllide a + O2 + NADPH
chlorophyllide b + H2O + NADP+
show the reaction diagram
chlorophyllide a + O2 + NADPH
7-hydroxychlorophyllide a + H2O + NADP+
show the reaction diagram
chlorophyllide a + O2 + NADPH
chlorophyllide b + H2O + NADP+
show the reaction diagram
chlorophyllide a + O2 + NADPH + H+
chlorophyllide b + 2 H2O + NADP+
show the reaction diagram
-
chlorophyll a precursor
immediately converted to chlorophyll b by chlorophyll synthase, the chlorophyllide a oxygenase activity is regulated at the level of protein stability via a feedback mechanism through chlorophyll b
-
?
chlorophyllide a + O2 + NADPH + H+
chlorophyllide b + H2O + NADP+
show the reaction diagram
chlorophyllide d + O2 + NADPH + H+
[7-formyl]-chlorophyllide d + H2O + NADP+
show the reaction diagram
-
-
-
-
?
protochlorophyllide a + O2 + NADPH
7-hydroxychlorophyllide a + H2O + NADP+
show the reaction diagram
-
low activity
-
-
?
Zn-7-hydroxy-Pheide a + O2 + NADPH
ZnPheide b + H2O + NADP+
show the reaction diagram
-
product identification
-
?
ZnPheide a + O2 + NADPH
Zn-7-hydroxy-Pheide a + H2O + NADP+
show the reaction diagram
-
product identification
-
?
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
7-hydroxychlorophyllide a + O2 + NADPH
chlorophyllide b + H2O + NADP+
show the reaction diagram
chlorophyllide a + O2 + NADPH
7-hydroxychlorophyllide a + H2O + NADP+
show the reaction diagram
chlorophyllide a + O2 + NADPH
chlorophyllide b + H2O + NADP+
show the reaction diagram
-
-
-
-
?
chlorophyllide a + O2 + NADPH + H+
chlorophyllide b + 2 H2O + NADP+
show the reaction diagram
-
chlorophyll a precursor
immediately converted to chlorophyll b by chlorophyll synthase, the chlorophyllide a oxygenase activity is regulated at the level of protein stability via a feedback mechanism through chlorophyll b
-
?
chlorophyllide a + O2 + NADPH + H+
chlorophyllide b + H2O + NADP+
show the reaction diagram
chlorophyllide d + O2 + NADPH + H+
[7-formyl]-chlorophyllide d + H2O + NADP+
show the reaction diagram
-
-
-
-
?
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Iron
-
the enzyme contains both Rieske and mononuclear iron-binding motifs. Ferredoxin reduces the Rieske center in subunit CAO1, which transfers electron to the mononuclear iron in subunit CAO2 where chlorophyll b is synthesized
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
additional information
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
-
small young cells adjacent to the epidermis cells with less frequent fusion enzyme signal (group III mutants), fusion enzyme signals only in small young cells adjacent to the epidermis cells (group V mutants - impaired chloroplast development with less chlorophyll)
Manually annotated by BRENDA team
-
low enzyme expression
Manually annotated by BRENDA team
-
cotyledons, uniform distribution of the fusion enzyme signal within the chloroplast (group 1 mutants - defects in specific steps of the chlorophyllide a enzyme regulation), punctate fusion enzyme signal (group II mutants - defect in chloroplast proteases), fusion enzyme signal only in guard cells (group VI mutants - slight inhibition of enzyme degradation or slightly enhanced enzyme synthesis)
Manually annotated by BRENDA team
-
cotyledons, uniform distribution of the fusion enzyme signal within the chloroplast (group I mutants - defects in specific steps of the chlorophyllide a enzyme regulation), punctate fusion enzyme signal (group II mutants - defect in chloroplast proteases), fusion enzyme signal dispersed within chloroplasts and at the same time high-intensity signals localized in confined areas within chloroplasts (group III mutants)
Manually annotated by BRENDA team
-
etiolated, high enzyme expression
Manually annotated by BRENDA team
additional information
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
-
only fusion enzyme localization (group VII mutant - defect in cellular trafficking of chloroplast proteins)
Manually annotated by BRENDA team
additional information
-
the enzyme is part of a separate translocon complex in chlorplasts
-
Manually annotated by BRENDA team
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
40000
-
2 * 40000, SDS-PAGE
40830
-
x * 40830, amino acid sequence calculation
48000
-
A and B domain + green fluorescence protein(AB-GFP) fusion enzyme, SDS-PAGE
54000
-
x * 54000, recombinant enzyme, SDS-PAGE
56000
-
full-length enzyme, SDS-PAGE
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
homodimer
-
2 * 40000, SDS-PAGE
additional information
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
a chloroplast Clp protease is involved in regulating chlorophyll b biosynthesis through the destabilization of CAO protein in response to the accumulation of chlorophyll b
-
the N-terminal domain of the enzyme confers protein instability in response to chlorophyll B accumulation
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
for immunoblotting analysis rosette leaves are homogenized with extraction buffer (50 mM Tris, pH 6.8, 2 mM EDTA, 10% glycerol, 2% SDS, 6% 2-mercaptoethanol), centrifugation, supernatant separated by SDS-PAGE, resolved proteins electroblotted onto Hybond-P membrane, identification of fusion enzyme signal with antibody-horseradish peroxidase system
-
partially by purification of chloroplast envelope inner membrane and thylakoid membranes
-
recombinant enzyme partially by purification of transgenic plant thylakoid membranes
-
refolded recombinant His6-tagged CAO from Escherichia coli by nickel affinity chromatography to about 85% purity
-
rosette leaves are homogenized with extraction buffer (50 mM Tris, pH 6.8, 2 mM EDTA, 10% glycerol, 2% SDS, 6% 2-mercaptoethanol), centrifugation, supernatants separated by SDS-PAGE, proteins electroblotted onto a Hybond-P membrane, identification of fusion enzyme with antibody-horseradish peroxidase system
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Arabidopsis which overexpress a CAO–GFP fusion are mutagenized
-
construction of a genomic library, DNA and amino acid sequence determination
DNA and amino acid sequence determination and analysis of wild-type and mutants genes, gene structures, overview
-
expressed in Acaryochloris marina strain MBIC 11017
-
expressed in Arabidopsis thaliana and in Escherichia coli C41 cells
-
expressed in Nicotiana tabacum cultivar Petit Havana
-
expression analysis with isolated nuclei
expression in Arabidopsis thaliana
-
expression in Escherichia coli in membranes, phylogenetic tree
-
expression of GFP-tagged enzyme in Chlamydomonas reinhardtii cells, phylogenetic tree
-
expression of GFP-tagged wild-type and GFP-tagged domain mutant enzymes in wild-type and enzyme-deficient chlorin-1 mutant plants
-
expression of His6-tagged CAO in Escherichia coli in inclusion bodies, in vitro expression by wheat germ lysates
-
expression of the enzyme under control of the 35S CaMV promoter, using the Agrobacterium tumefaciens infection system, in transgenic Arabidopsis thaliana plants renders the transgenic plants capable of normal rate photosynthetic growth also under low light conditions in contrast to the wild-type Arabidopsis thaliana plants, transgenic plants show altered chlorophyll a/b ratio, chloroplast structure, and thylakoid membrane composition; introductionof the prokaryotic chlorophyll b synthesis gene for chlorophyllide a oxygenase (CAO) into Arabidopsis. In the transgenic plants (Prochlirothrix hollandica CAO plants), about 40% of chlorophyll a of the core antenna complexes is replaced by chlorophyll b in both photosystems
-
functional expression in Escherichia coli
functional overexpression in transgenic tobacco plants via Agrobacterium tumefaciens LBA4404 transfection, the CAO gene is expressed under control of the 35S CaMV promoter
-
gene CAO, DNA and amino acid sequence determination and analysis, genetic organization
introduction of the Prochlorococcus gene into Synechocystis cells
-
overexpression of the enzyme in Arabidopsis thaliana plants
-
pGreenII-0029 plasmid vector with fusion enzyme is introduced into Agrobacterium tumefaciens strain C58 by electroporation, wild-type and chlorina1-1 mutants of Arabidopsis thaliana are transformed by the infiltration with the bacterium, plant transformants are selected
-
plasmid vector pGreenII-0029 including the gene for the green fluorescent protein fused with full-length or truncated chlorophyllide a oxygenase, plasmid with fusion enzyme is then transformed into Agrobacterium tumefaciens (strain GV2260) by electroporation, wild-type Arabidopsis and chlorina1-1 mutant are transformed by vacuum infiltration
-
single-copy CAO gene, amino aid sequence and N-terminal extensions comparison with other higher plant sequences and the sequence of the algae Prochlorothrix hollandica, functional expression of ABC, BC, and C domain constructs in Synechocystis sp. PCC6803 reveals that the C domain is sufficient for catalytic activity
single-copy CAO gene, DNA and amino acid sequence determination and analysis, amino aid sequence and N-terminal extensions comparison with higher plant sequences, e.g. of Arabidopsis thaliana, functional expression in Synechocystis sp. PCC6803
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
E136V
-
amino acid mutation within A-domain, increased stability of the fusion enzyme, K157R alone without stability effect, deletions from Q97 up to or beyond H106 result in stability signal equivalent to a lack of the entire A-domain
A376V
the mutant shows reduced activity compared to the wild type enzyme
A94T
the mutant shows reduced activity compared to the wild type enzyme
C320Y
the mutant shows reduced activity compared to the wild type enzyme
D495N
inactive
G280D
inactive
L373F
the mutant shows reduced activity compared to the wild type enzyme
P419L
the mutant shows reduced activity compared to the wild type enzyme
additional information
Renatured/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
solubilization of recombinant His6-tagged enzyme from inclusion bodies after expression in Escherichia coli by 8 M urea and refolding
-