Cloned (Comment) | Organism |
---|---|
expression of mutant enzymes in Escherichia coli strain BL21(DE3) | Synechocystis sp. |
Crystallization (Comment) | Organism |
---|---|
purified recombinant mutant enzymes, hanging drop vapour diffusion method, dithionite-treated reduced D105N PcyA crystals from 1.45-1.8 M ammonium sulfate, 0.15-0.4 M NaCl, and 0.1 M HEPES, pH 7.0, dithionite-treated reduced H88Q PcyA crystals from 1.7-2.2 M ammonium sulfate, 0.26-0.32 M NaCl, and 0.1 M sodium cacodylate, pH 7.0, 20°C in the dark, cryoprotectant solution is consisting of 30% v/v ethylene glycol in mother liquor, X-ray diffraction structure determination and analysis at 1.5 A resolution | Synechocystis sp. |
Protein Variants | Comment | Organism |
---|---|---|
D105N | site-directed mutagenesis | Synechocystis sp. |
H88Q | site-directed mutagenesis | Synechocystis sp. |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
biliverdin Ixalpha + reduced ferredoxin | Synechocystis sp. | - |
(3Z)-phycocyanobilin + oxidized ferredoxin | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Synechocystis sp. | - |
- |
- |
Purification (Comment) | Organism |
---|---|
recombinant mutant enzymes from Escherichia coli strain BL21(DE3) by cyanide affinity chromatography | Synechocystis sp. |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
biliverdin Ixalpha + reduced ferredoxin | - |
Synechocystis sp. | (3Z)-phycocyanobilin + oxidized ferredoxin | - |
? |
Subunits | Comment | Organism |
---|---|---|
More | both PcyA D105N and H88Q mutants adopt alpha/beta/alpha sandwich folds possessing a central seven-stranded antiparallel beta-sheet lying between four alpha-helixes on each side | Synechocystis sp. |
Synonyms | Comment | Organism |
---|---|---|
PcyA | - |
Synechocystis sp. |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
Ferredoxin | - |
Synechocystis sp. |
General Information | Comment | Organism |
---|---|---|
metabolism | phycocyanobilin:ferredoxin oxidoreductase, PcyA, is a key enzyme in the biogenesis of heme-derived linear tetrapyrroles, phytobilins, it catalyzes the overall four-electron reduction of biliverdin IXalpha to phycocyanobilin, the common chromophore precursor for both classes of biliproteins | Synechocystis sp. |
additional information | the interconversion occurs via semireduced bilin radical intermediates that are profoundly stabilized by selected mutations of two critical catalytic residues, Asp105 and His88. Mechanistic scheme for PcyA-mediated reduction of both vinyl groups of biliverdin wherein an axial water molecule, which prematurely binds and ejects from both mutants upon one electron reduction, is required for catalytic turnover of the semireduced state, structure-function relationship, overview | Synechocystis sp. |