Repeated Chemical Changes to l-Tryptophan in Psilocybe Evolved Through Copying of Protein Sections

A second enzyme, TrpM, was identified in Psilocybe serbica that mono- and dimethylates l-tryptophan, but not tryptamine.

• TrpM is distinct from the previously known enzyme PsiM, which is involved in psilocybin biosynthesis.
• The activity of TrpM is linked to a second pathway in Psilocybe that does not contribute to psilocybin production.
• The retention of TrpM in Psilocybe is associated with an ancient gene duplication event related to ergothioneine biosynthesis.
• This gene duplication event appears to have been lost in many species but has independently re-evolved in different mushroom genera.
• The findings suggest a mechanism for the evolution of secondary metabolic pathways through the preservation of certain genes.

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