Activating Compound | Comment | Organism | Structure |
---|---|---|---|
additional information | the catalytic activity of RCCR in vitro dramatically increases by coupling with pheophorbide alpha oxygenase, which also results in a stereospecific product | Arabidopsis thaliana | |
additional information | the catalytic activity of RCCR in vitro dramatically increases by coupling with PaO, possibly due to cooperative action, although PaO has been localized to the plastid envelope and RCCR is a soluble stroma enzyme | Arabidopsis thaliana |
Cloned (Comment) | Organism |
---|---|
cloning and expression in Escherichia coli | Arabidopsis thaliana |
Crystallization (Comment) | Organism |
---|---|
at 2.4 A resolution, determination of the crystal structure of, where chloroplast transit peptide is truncated and a Gly-Pro-Leu-Gly-Ser peptide is added to the N terminus, 2 peptide chains A and B are located in an asymmetric unit of the selenomethionine-RCCR crystal, these 2 chains form a homodimer, AtRCCR folds into an alpha/beta/alpha sandwich: 5 N-terminal alpha-helices, an anti-parallel beta-sheet consisting of 8 strands, and 4 C-terminal alpha-helices | Arabidopsis thaliana |
purified substrate-free enzyme, with the chloroplast transit peptide truncated and a Gly-Pro-Leu-Gly-Ser peptide added to the N-terminus, X-ray diffraction structure determination and analysis at 2.5-2.7 A resolution, structure modelling | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
chloroplast | mainly | Arabidopsis thaliana | 9507 | - |
chloroplast | stroma, constitutive enzyme, the N-terminal 39-amino-acid stretch of RCCR is predicted to be the chloroplast transit peptide | Arabidopsis thaliana | 9507 | - |
mitochondrion | in young seedlings and in response to stress, RCCR is somewhat localized to mitochondria | Arabidopsis thaliana | 5739 | - |
additional information | RCCR is constitutively expressed in chloroplasts, whereas in young seedlings and in response to stress, it is also localized to mitochondria | Arabidopsis thaliana | - |
- |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
32000 | - |
2 * 32000, predicted by amino acid sequence, each subunit folds in an alpha/beta/alpha sandwich | Arabidopsis thaliana |
32000 | - |
2 * 32000, about, sequence calculation | Arabidopsis thaliana |
60000 | - |
about, gel filtration | Arabidopsis thaliana |
60000 | - |
dimer, determined by gel filtration | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
red chlorophyll catabolite + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H+ | Arabidopsis thaliana | - |
primary fluorescent chlorophyll catabolite + 2 oxidized ferredoxin [iron-sulfur] cluster | - |
? | |
red chlorophyll catabolite + reduced acceptor | Arabidopsis thaliana | the key steps in the degradation pathway of chlorophylls are the ring-opening reaction catalyzed by pheophorbide a oxygenase and sequential reduction by RCCR, RCCR catalyzes the ferredoxin-dependent reduction of the C20/C1 double bond of red chlorophyll catabolite | primary fluorescent chlorophyll catabolite + oxidized acceptor | in the acidic environment of vacuoles, primary fluorescent chlorophyll catabolite is spontaneously converted into nonfluorescent chlorophyll catabolites | ? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q8LDU4 | - |
- |
Purification (Comment) | Organism |
---|---|
anion exchange chromatography | Arabidopsis thaliana |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
red chlorophyll catabolite + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H+ | - |
Arabidopsis thaliana | primary fluorescent chlorophyll catabolite + 2 oxidized ferredoxin [iron-sulfur] cluster | - |
? | |
red chlorophyll catabolite + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H+ | - |
Arabidopsis thaliana | primary fluorescent chlorophyll catabolite + 2 oxidized ferredoxin [iron-sulfur] cluster | formation of a stereospecific product, overview | ? | |
red chlorophyll catabolite + reduced acceptor | the key steps in the degradation pathway of chlorophylls are the ring-opening reaction catalyzed by pheophorbide a oxygenase and sequential reduction by RCCR, RCCR catalyzes the ferredoxin-dependent reduction of the C20/C1 double bond of red chlorophyll catabolite | Arabidopsis thaliana | primary fluorescent chlorophyll catabolite + oxidized acceptor | in the acidic environment of vacuoles, primary fluorescent chlorophyll catabolite is spontaneously converted into nonfluorescent chlorophyll catabolites | ? |
Subunits | Comment | Organism |
---|---|---|
homodimer | 2 * 32000, predicted by amino acid sequence, each subunit folds in an alpha/beta/alpha sandwich | Arabidopsis thaliana |
homodimer | 2 * 32000, about, sequence calculation | Arabidopsis thaliana |
More | enzyme RCCR forms a homodimer, in which each subunit folds in an alphabetaalpha sandwich, five N-terminal alpha-helices (H1/H2/H3/H5/H7), an anti-parallel beta-sheet consisting of eight strands (S1-S8), and four C-terminal alpha-helices (H4/H6/H8/H9). The two subunits are related by noncrystallographic 2fold symmetry in which the alpha-helices near the edge of the beta-sheet unique in RCCR participate in intersubunit interaction. The putative RCC-binding site forms an open pocket surrounded by conserved residues among RCCRs. Residues Glu154 and Asp291 stand opposite each other in the substrate binding pocket and are likely involved in substrate binding and/or catalysis. Primary structure comparisons, overview | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
RCCR | - |
Arabidopsis thaliana |
red chlorophyll catabolite reductase | - |
Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
Ferredoxin | - |
Arabidopsis thaliana | |
Ferredoxin | dependent on | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme belongs to the ferredoxin-dependent bilin reductase (FDBR) family, which synthesizes a variety of phytobilin pigments, on the basis of sequence similarity, ferredoxin dependency, and the common tetrapyrrole skeleton of their substrates. The tertiary structure of RCCR is similar to those of FDBRs, strongly supporting that these enzymes evolved from a common ancestor | Arabidopsis thaliana |
additional information | Residues Glu154 and Asp291 stand opposite each other in the substrate binding pocket and are likely involved in substrate binding and/or catalysis | Arabidopsis thaliana |
physiological function | the key steps in the degradation pathway of chlorophylls are the ring opening reaction catalyzed by pheophorbide a oxygenase and sequential reduction by red chlorophyll catabolite reductase (RCCR). During these steps, chlorophyll catabolites lose their color and phototoxicity. Enzyme RCCR catalyzes the ferredoxin-dependent reduction of the C20/C1 double bond of red chlorophyll catabolite | Arabidopsis thaliana |