Enzymes
UniProtKB help_outline | 775 proteins |
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Reaction participants Show >> << Hide
- Name help_outline (2R,3Z)-phycocyanobilin Identifier CHEBI:57437 Charge -2 Formula C33H36N4O6 InChIKeyhelp_outline XAVVMXGLKJSJDU-NSNBCYBJSA-L SMILEShelp_outline CCC1=C(C)\C(NC1=O)=C\c1[nH]c(\C=C2/N=C(/C=C3NC(=O)[C@H](C)C\3=C\C)C(C)=C/2CCC([O-])=O)c(CCC([O-])=O)c1C 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
oxidized [2Fe-2S]-[ferredoxin]
Identifier
RHEA-COMP:10000
Reactive part
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- Name help_outline [2Fe-2S]2+ Identifier CHEBI:33737 Charge 2 Formula Fe2S2 InChIKeyhelp_outline XSOVBBGAMBLACL-UHFFFAOYSA-N SMILEShelp_outline S1[Fe+]S[Fe+]1 2D coordinates Mol file for the small molecule Search links Involved in 238 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline biliverdin IXα Identifier CHEBI:57991 Charge -2 Formula C33H32N4O6 InChIKeyhelp_outline QBUVFDKTZJNUPP-BBROENKCSA-L SMILEShelp_outline C=1(/C=C/2\NC(=O)C(=C2C=C)C)NC(=C(C1C)CCC([O-])=O)/C=C/3\N=C(/C=C/4\NC(C(=C4C)C=C)=O)C(=C3CCC([O-])=O)C 2D coordinates Mol file for the small molecule Search links Involved in 10 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
reduced [2Fe-2S]-[ferredoxin]
Identifier
RHEA-COMP:10001
Reactive part
help_outline
- Name help_outline [2Fe-2S]1+ Identifier CHEBI:33738 Charge 1 Formula Fe2S2 InChIKeyhelp_outline MAGIRAZQQVQNKP-UHFFFAOYSA-N SMILEShelp_outline S1[Fe]S[Fe+]1 2D coordinates Mol file for the small molecule Search links Involved in 238 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:15309 | RHEA:15310 | RHEA:15311 | RHEA:15312 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Functional genomic analysis of the HY2 family of ferredoxin-dependent bilin reductases from oxygenic photosynthetic organisms.
Frankenberg N., Mukougawa K., Kohchi T., Lagarias J.C.
Phytobilins are linear tetrapyrrole precursors of the light-harvesting prosthetic groups of the phytochrome photoreceptors of plants and the phycobiliprotein photosynthetic antennae of cyanobacteria, red algae, and cryptomonads. Previous biochemical studies have established that phytobilins are sy ... >> More
Phytobilins are linear tetrapyrrole precursors of the light-harvesting prosthetic groups of the phytochrome photoreceptors of plants and the phycobiliprotein photosynthetic antennae of cyanobacteria, red algae, and cryptomonads. Previous biochemical studies have established that phytobilins are synthesized from heme via the intermediacy of biliverdin IX alpha (BV), which is reduced subsequently by ferredoxin-dependent bilin reductases with different double-bond specificities. By exploiting the sequence of phytochromobilin synthase (HY2) of Arabidopsis, an enzyme that catalyzes the ferredoxin-dependent conversion of BV to the phytochrome chromophore precursor phytochromobilin, genes encoding putative bilin reductases were identified in the genomes of various cyanobacteria, oxyphotobacteria, and plants. Phylogenetic analyses resolved four classes of HY2-related genes, one of which encodes red chlorophyll catabolite reductases, which are bilin reductases involved in chlorophyll catabolism in plants. To test the catalytic activities of these putative enzymes, representative HY2-related genes from each class were amplified by the polymerase chain reaction and expressed in Escherichia coli. Using a coupled apophytochrome assembly assay and HPLC analysis, we examined the ability of the recombinant proteins to catalyze the ferredoxin-dependent reduction of BV to phytobilins. These investigations defined three new classes of bilin reductases with distinct substrate/product specificities that are involved in the biosynthesis of the phycobiliprotein chromophore precursors phycoerythrobilin and phycocyanobilin. Implications of these results are discussed with regard to the pathways of phytobilin biosynthesis and their evolution. << Less
Plant Cell 13:965-978(2001) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.
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Phycocyanobilin is the natural precursor of the phytochrome chromophore in the green alga Mesotaenium caldariorum.
Wu S.H., McDowell M.T., Lagarias J.C.
Compared with phytochromes isolated from etiolated higher plant tissues and a number of lower plant species, the absorption spectrum of phytochrome isolated from the unicellular green alga Mesotaenium caldariorum is blue-shifted (Kidd, D. G., and Lagarias, J. C. (1990) J. Biol. Chem. 265, 7029-703 ... >> More
Compared with phytochromes isolated from etiolated higher plant tissues and a number of lower plant species, the absorption spectrum of phytochrome isolated from the unicellular green alga Mesotaenium caldariorum is blue-shifted (Kidd, D. G., and Lagarias, J. C. (1990) J. Biol. Chem. 265, 7029-7035). The present studies were undertaken to determine whether this blue shift is due to a chromophore other than phytochromobilin or reflects a different protein environment for the phytochromobilin prosthetic group. Using reversed phase high performance liquid chromatography, we show that soluble protein extracts prepared from algal chloroplasts contain the enzyme activities for ferredoxin-dependent conversions of biliverdin IXalpha to (3Z)-phytochromobilin and (3Z)-phytochromobilin to (3Z)-phycocyanobilin. In vitro assembly of recombinant algal apophytochrome was undertaken with (3E)-phytochromobilin and (3E)-phycocyanobilin. The difference spectrum of the (3E)-phycocyanobilin adduct was indistinguishable from that of phytochrome isolated from dark-adapted algal cells, while the (3E)-phytochromobilin adduct displayed red-shifted absorption maxima relative to purified algal phytochrome. These studies indicate that phycocyanobilin is the immediate precursor of the green algal phytochrome chromophore and that phytochromobilin is an intermediate in its biosynthesis in Mesotaenium. << Less