Evolutionary convergence in lignin-degrading enzymes
Proc. Natl. Acad. Sci. USA, 115: 6428-6433
Ayuso-Fernández I, Ruiz-Dueñas FJ, Martínez AT
We analyze the molecular mechanisms that led to the rise of a powerful strategy for lignin degradation (i.e., the formation of a solvent-exposed tryptophanyl radical capable of oxidizing the bulky lignin polymer) as a convergent trait in different species of fungi (order Polyporales). We use ancestral sequence reconstruction and enzyme resurrection to obtain the ancestors of the two extant types of ligninolytic peroxidases—lignin peroxidase (LiP) and versatile peroxidase (VP)—and compare their predicted molecular structures and catalytic properties after resurrection. The results presented demonstrate convergent evolution in distant LiP and VP lineages with the exposed tryptophan residue appearing twice, as two independent events, following different molecular changes.