Discovery of Gene Cluster for Mycosporine-Like Amino Acid Biosynthesis from Actinomycetales Microorganisms and Production of a Novel Mycosporine-Like Amino Acid by Heterologous Expression

Abstract

Mycosporines and mycosporine-like amino acids (MAAs), including shinorine (mycosporine-glycine-serine) and porphyra-334 (mycosporine-glycine-threonine), are UV-absorbing compounds produced by cyanobacteria, fungi, and marine micro-and macroalgae. These MAAs have the ability to protect these organisms from damage by environmental UV radiation. Although no reports have described the production of MAAs and the corresponding genes involved in MAA biosynthesis from Gram-positive bacteria to date, genome mining of the Gram-positive bacterial database revealed that two microorganisms belonging to the order Actinomycetales, Actinosynnema mirum DSM 43827 and Pseudonocardia sp. strain P1, possess a gene cluster homologous to the biosynthetic gene clusters identified from cyanobacteria. When the two strains were grown in liquid culture, Pseudonocardia sp. accumulated a very small amount of MAA-like compound in a medium-dependent manner, whereas A. mirum did not produce MAAs under any culture conditions, indicating that the biosynthetic gene cluster of A. mirum was in a cryptic state in this microorganism. In order to characterize these biosynthetic gene clusters, each biosynthetic gene cluster was heterologously expressed in an engineered host, Streptomyces avermitilis SUKA22. Since the resultant transformants carrying the entire biosynthetic gene cluster controlled by an alternative promoter produced mainly shinorine, this is the first confirmation of a biosynthetic gene cluster for MAA from Gram-positive bacteria. Furthermore, S. avermitilis SUKA22 transformants carrying the biosynthetic gene cluster for MAA of A. mirum accumulated not only shinorine and porphyra-334 but also a novel MAA. Structure elucidation revealed that the novel MAA is mycosporine-glycine-alanine, which substitutes L-alanine for the L-serine of shinorine.

Heterologous Production of Cyanobacterial Mycosporine-Like Amino Acids Mycosporine-Ornithine and Mycosporine-Lysine in Escherichia coli

“…In A. halophytica, attachment of a second glycine residue in this same position, forming mycosporine-2-glycine, is catalyzed by a D-AlaϪD-Ala ligase homologue (Ap_3855) (23). Similarly, in A. mirum, attachment of alanine or serine to form mycosporine-glycine-alanine and shinorine is catalyzed by a D-AlaϪD-Ala ligase (24). Taken together, these data suggest that the fourth enzyme in the MAA biosynthesis pathway, a D-AlaϪD-Ala ligase, is responsible for much of the diversity observed in MAA-like compounds.…”

“…2), N. punctiforme ATCC 29133, A. halophytica, Actinosynnema mirum DSM 43827, and Microcystis aeruginosa sp. PCC 7806 (19,21,(23)(24)(25). Several MAA-like compounds contain a second amino acid residue attached to the 1 position of mycosporine-glycine.…”

Can Fortified Bifidobacterium with Mycosporin-like Amino Acid be a New Insight for Neurological Disease' s Treatment?

“…Trans-aldolase is an enzyme of the non-oxidative phase of the pentose phosphate pathway and Bifidobacterium strains have transaldolase enzyme. Confirmation of a biosynthetic gene cluster for MAAs from Gram-positive bacteria has been showed [31]. Anabaena variabilist PCC 7937 (Cyanobacterium) is able to synthesize MAAs [32].…”

Mild Acid Hydrolysis-related Release of Water-soluble Sunscreen Pigments from the Exopolysaccharide Matrix of Edible Terrestrial Cyanobacteria

“…More than 30 different compounds in the mycosporine family have been identified from natural sources, including cyanobacteria, fungi and marine algae [2,3]. These UV-absorbing molecules (herein all referred to as MAAs) can dissipate the absorbed UV radiation as heat without the generation of reactive oxygen species [4].…”

“…Mycosporines and mycosporine-like amino acids (MAAs) are small (<400 Da), colorless and water-soluble molecules, with strong ultraviolet (UV) absorption maxima from 310 to 365 nm [1,2]. More than 30 different compounds in the mycosporine family have been identified from natural sources, including cyanobacteria, fungi and marine algae [2,3].…”