Activating Compound | Comment | Organism | Structure |
---|---|---|---|
4-methylideneimidazole-5-one | - |
Taxus chinensis |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Taxus chinensis | Q68G84 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-phenylalanine | - |
Taxus chinensis | L-beta-phenylalanine | when L-Phe enters the active site, the carboxylate group forms a bidentate salt bridge with residue R325. The carboxylate group further interacts with residue Q319. The amine group and the pro-3S hydrogen atom are oriented in an anti-periplanar geometry suitable for the elimination step. A nucleophilic attack of the amine group of the substrate on the 4-methylideneimidazole-5-one cofactor group preceeds abstraction of the proton by the general base Y80, possibly assisted by another basic group, and elimination of 4-methylideneimidazole-5-one-NH2. This leads to formation of trans-cinnamic acid, with the carboxylate group still bound to residue R325. The next step is the readdition of 4-methylideneimidazole-5-one-NH2 to the beta-position and of the proton to the alpha-position. This step requires exposure of the Re face of Cbeta to the 4-methylideneimidazole-5-one-NH2 and the carboxylate group to function as a good electron sink | r | |
additional information | enzyme additionally displays ammonia lyase activity, EC. 4.3.1.24, catalyzing the elimination of ammonia from L-phenylalanine to give trans-cinnamate | Taxus chinensis | ? | - |
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