Protein Variants | Comment | Organism |
---|---|---|
T135A | site-directed mutagenesis, inactive mutant | Sorbus aucuparia |
T135F | site-directed mutagenesis, the mutant functionally resembles the wild-type enzyme | Sorbus aucuparia |
T135G | site-directed mutagenesis, inactive mutant | Sorbus aucuparia |
T135I | site-directed mutagenesis, inactive mutant | Sorbus aucuparia |
T135L | site-directed mutagenesis, the benzophenone synthaase is converted into a functional phenylpyrone synthase by the single amino acid substitution in the initiation/elongation cavity, chalcone synthase-based homology modeling, overview. The intermediate triketide may be redirected into a smaller pocket in the active site cavity, resulting in phenylpyrone formation by lactonization. Compared with the initiation/elongation cavity of BPS, the size of the newly accessible pocket in PPS is smaller and does not allow for a third acetyl addition to the growing polyketide chain, resulting in the release of the intermediate triketide as 6-phenyl-4-hydroxy-2-pyrone | Sorbus aucuparia |
T135N | site-directed mutagenesis, inactive mutant | Sorbus aucuparia |
T135S | site-directed mutagenesis, the mutant functionally resembles the wild-type enzyme | Sorbus aucuparia |
T135V | site-directed mutagenesis, inactive mutant | Sorbus aucuparia |
T135Y | site-directed mutagenesis, inactive mutant | Sorbus aucuparia |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
3 malonyl-CoA + benzoyl-CoA | Sorbus aucuparia | - |
4 CoA + 2,4,6-trihydroxybenzophenone + 3 CO2 | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Sorbus aucuparia | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 malonyl-CoA + benzoyl-CoA | reaction of mutant T135L, no activity with the wild-type enzyme. The T135L mutant adds only two acetyl groups to the benzoyl starter unit to form a triketide intermediate which then cyclized into 6-phenyl-4-hydroxy-2-pyrone via C5 keto-enol oxygen -> C1 lactonization | Sorbus aucuparia | 3 CoA + 6-phenyl-4-hydroxy-2-pyrone + 2 CO2 | - |
? | |
3 malonyl-CoA + benzoyl-CoA | - |
Sorbus aucuparia | 4 CoA + 2,4,6-trihydroxybenzophenone + 3 CO2 | - |
? | |
3 malonyl-CoA + benzoyl-CoA | benzoyl-CoA is the preferred starter substrate of the wild-type enzyme, very low 2,4,6-trihydroxybenzophenone-forming activity with the mutant T135L | Sorbus aucuparia | 4 CoA + 2,4,6-trihydroxybenzophenone + 3 CO2 | - |
? | |
additional information | 3-hydroxybenzoyl-CoA is the second best starter substrate for the wild-type enzyme but a poor starter molecule for the mutant enzyme T135L, resulting in formation of 2,3',4,6-tetrahydroxybenzophenone, reaction of EC 2.3.1.151. The benzoyl-primed triketides are covalently attached to the catalytic Cys167. The wild-type enzyme catalyzes another acetyl addition to the intermediate triketide | Sorbus aucuparia | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
benzophenone synthase | - |
Sorbus aucuparia |
BPS | - |
Sorbus aucuparia |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
35 | - |
- |
Sorbus aucuparia |
General Information | Comment | Organism |
---|---|---|
evolution | biphenyl synthase and benzophenone synthase catalyze the formation of identical linear tetraketide intermediates from benzoyl-CoA and three molecules of malonyl-CoA but use alternative intramolecular cyclization reactions to form 3,5-dihydroxybiphenyl and 2,4,6-trihydroxybenzophenone, respectively, phylogenetic analysis, overview. The enzyme belongs to the type iIi polyketide synthase superfamily. The functionally diverse PKSs, which include BIS and BPS, and the ubiquitously distributed chalcone synthases form separate clusters, which originate from a gene duplication event prior to the speciation of the angiosperms | Sorbus aucuparia |
malfunction | the benzophenone synthaase is converted into a functional phenylpyrone synthase by the single amino acid substitution T135L in the initiation/elongation cavity, homology modeling. The intermediate triketide may be redirected into a smaller pocket in the active site cavity, resulting in phenylpyrone formation by lactonization | Sorbus aucuparia |
metabolism | BPS is the key enzyme of benzophenone metabolism | Sorbus aucuparia |
additional information | the catalytic triad is formed by Cys167, His307, aand Asn340 | Sorbus aucuparia |