Discovery and characterization of arsenic-containing ribosomally synthesized and post-translationally modified peptides (AsRiPP): a potential novel antimicrobial peptide from Roseimarinus sediminis
Primary Investigator (PI) Name
Masafumi Yoshinaga
Department
CSM – Molecular and Cellular Biology
Abstract
Arsenic, a widely recognized environmental toxin, surprisingly shows promise in medicine. Antimicrobial resistance poses a global health crisis, highlighting the urgent need for new potent antimicrobials. Notably, bacteria leverage environmental arsenic to synthesize unique antibiotics, as represented by arsinothricin (AST), a recently identified arsenic-containing antibiotic. AST is effective against multiple pathogens while exhibiting low toxicity on human cell lines, demonstrating the potential of arsenic-based natural products as antimicrobials. This project aims to identify additional novel arsenic-containing antibiotics. AST biosynthesis involves two arsenic-biotransforming enzymes, ArsL and ArsM. arsL/arsM-guided genome mining identified several prospective biosynthetic gene clusters (BGCs) for new arsenic-containing antibiotics. Among them, this work focuses on the arsM-containing BGC from Roseimarinus sediminis. The BGC contains genes for a SPASM-domain radical S-adenosylmethionine (SAM) enzyme, which is often involved in biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), along with a short gene that is predicted to be for a RiPP precursor peptide. Its most distinctive feature is the presence of arsM, encoding an arsenic SAM methyltransferase. It is therefore hypothesized that this cluster produces an arsenic-containing RiPP, named AsRiPP, where methylated arsenic species produced by ArsM is incorporated into the peptide during maturation. When R. sediminis was cultured with arsenite, an unknown arsenic species was produced. This compound, which was crudely purified through column chromatography, exhibited antibiotic activity, suggesting that R. sediminis produces a novel arsenic-containing antibiotic, presumably the AsRiPP. Further purification and analyses will be performed to identify the compound. In parallel, Escherichia coli strains expressing the precursor peptide gene solely or co-expressing it with the other AsRiPP gene(s) were constructed, and some of the gene expression was successfully confirmed. These constructs are being analyzed to elucidate the biosynthetic pathway and verify the association between the AsRiPP BGC and the bioactive arsenic compound produced by R. sediminis.
Disciplines
Amino Acids, Peptides, and Proteins | Biochemistry | Environmental Microbiology and Microbial Ecology | Integrative Biology | Microbiology | Molecular Biology | Organic Chemicals
Discovery and characterization of arsenic-containing ribosomally synthesized and post-translationally modified peptides (AsRiPP): a potential novel antimicrobial peptide from Roseimarinus sediminis
Arsenic, a widely recognized environmental toxin, surprisingly shows promise in medicine. Antimicrobial resistance poses a global health crisis, highlighting the urgent need for new potent antimicrobials. Notably, bacteria leverage environmental arsenic to synthesize unique antibiotics, as represented by arsinothricin (AST), a recently identified arsenic-containing antibiotic. AST is effective against multiple pathogens while exhibiting low toxicity on human cell lines, demonstrating the potential of arsenic-based natural products as antimicrobials. This project aims to identify additional novel arsenic-containing antibiotics. AST biosynthesis involves two arsenic-biotransforming enzymes, ArsL and ArsM. arsL/arsM-guided genome mining identified several prospective biosynthetic gene clusters (BGCs) for new arsenic-containing antibiotics. Among them, this work focuses on the arsM-containing BGC from Roseimarinus sediminis. The BGC contains genes for a SPASM-domain radical S-adenosylmethionine (SAM) enzyme, which is often involved in biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), along with a short gene that is predicted to be for a RiPP precursor peptide. Its most distinctive feature is the presence of arsM, encoding an arsenic SAM methyltransferase. It is therefore hypothesized that this cluster produces an arsenic-containing RiPP, named AsRiPP, where methylated arsenic species produced by ArsM is incorporated into the peptide during maturation. When R. sediminis was cultured with arsenite, an unknown arsenic species was produced. This compound, which was crudely purified through column chromatography, exhibited antibiotic activity, suggesting that R. sediminis produces a novel arsenic-containing antibiotic, presumably the AsRiPP. Further purification and analyses will be performed to identify the compound. In parallel, Escherichia coli strains expressing the precursor peptide gene solely or co-expressing it with the other AsRiPP gene(s) were constructed, and some of the gene expression was successfully confirmed. These constructs are being analyzed to elucidate the biosynthetic pathway and verify the association between the AsRiPP BGC and the bioactive arsenic compound produced by R. sediminis.