Heterologous Production of Cyanobacterial Mycosporine-Like Amino Acids Mycosporine-Ornithine and Mycosporine-Lysine in Escherichia coli
ABSTRACTMycosporine-like amino acids (MAAs) are an important class of secondary metabolites known for their protection against UV radiation and other stress factors. Cyanobacteria produce a variety of MAAs, including shinorine, the active ingredient in many sunscreen creams. Bioinformatic analysis of the genome of the soil-dwelling cyanobacteriumCylindrospermum stagnalePCC 7417 revealed a new gene cluster with homology to MAA synthase fromNostoc punctiforme. This newly identified gene cluster is unusual because it has five biosynthesis genes (mylAtomylE), compared to the four found in other MAA gene clusters. Heterologous expression ofmylAtomylEinEscherichia coliresulted in the production of mycosporine-lysine and the novel compound mycosporine-ornithine. To our knowledge, this is the first time these compounds have been heterologously produced inE. coliand structurally characterized via direct spectral guidance. This study offers insight into the diversity, biosynthesis, and structure of cyanobacterial MAAs and highlights their amenability to heterologous production methods.IMPORTANCEMycosporine-like amino acids (MAAs) are significant from an environmental microbiological perspective as they offer microbes protection against a variety of stress factors, including UV radiation. The heterologous expression of MAAs inE. coliis also significant from a biotechnological perspective as MAAs are the active ingredient in next-generation sunscreens.