The Genetic and Molecular Basis for Sunscreen Biosynthesis in Cyanobacteria

Abstract

Enzymes for Sunscreen Synthesis Many fungi, cyanobacteria, algae, and other marine organisms can biosynthesize small molecules termed mycosporine and mycosporine-like amino acids (MAAs) that, among other functions, protect them from harmful UV exposure. A formulation containing MAAs is used as a sunscreen in skin care and cosmetic products. Balskus and Walsh (p. 1653 , published online 2 September) have now identified the gene cluster in a cyanobacterium that is responsible for MAA production. They expressed the cluster in Escherichia coli and characterized the four biosynthetic enzymes bio chemically. Two are adenosine triphosphate.dependent peptide bond.forming enzymes that catalyze imine bond formation through unusual mechanisms.