Fusion Enzymes Involved in Biosynthetic Tailoring Reactions in Fungi

Enzyme fusion, the fusion of enzymes with different domains to a single protein, has been widely recognized as a promising strategy in the development of biocatalysts. Nature has evolved gene fusion to combine different catalytic enzymes to function as a fusion enzyme, and this strategy is utilized in many natural product biosynthetic pathways. Owing to rapid advances in genome sequencing and biosynthetic pathway characterization, there is increasing interest in fusion enzymes from fungal biosynthetic pathways, particularly those involved in tailoring steps. This concept aims to provide an up‐to‐date overview of fusion enzymes that catalyze tailoring reactions in the biosynthesis of fungal secondary metabolites. Since fungal fusion enzymes are often associated with novel metabolites, this pioneering work may stimulate the exploration of the structural diversity of fungal natural products through genome mining of the untapped biosynthetic pathways involving fusion enzymes. Fusion enzymes are single proteins consisting of two or more functional domains, which have been increasingly reported from the biosynthesis of fungal natural products. This concept provides an up‐to‐date summary of the characterized fusion enzymes responsible for catalyzing biosynthetic tailoring reactions in fungi.