Heterologous Expression of Mersacidin in Escherichia coli Elucidates the Mode of Leader Processing

Jakob H Viel, Ate H Jaarsma, Oscar P Kuipers*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The lanthipeptide mersacidin is a ribosomally synthesized and post-translationally modified peptide (RiPP) produced by Bacillus amyloliquefaciens. It has antimicrobial activity against a range of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, giving it potential therapeutic relevance. The structure and bioactivity of mersacidin are derived from a unique combination of lanthionine ring structures, which makes mersacidin also interesting from a lantibiotic-engineering point of view. Until now, mersacidin and its derivatives have exclusively been produced in Bacillus strains and purified from the supernatant in their bioactive form. However, to fully exploit its potential in lanthipeptide-engineering, mersacidin would have to be expressed in a standardized expression system and obtained in its inactive prepeptide form. In such a system, the mersacidin biosynthetic enzymes could be employed to create novel peptides, enhanced by the recent advancements in RiPP engineering, while the leader peptide prevents activity against the expression host. This system would however need a means of postpurification in vitro leader processing to activate the obtained precursor peptides. While mersacidin's native leader processing mechanism has not been confirmed, the bifunctional transporter MrsT and extracellular Bacillus proteases have been suggested to be responsible. Here, a modular system is presented for the heterologous expression of mersacidin in Escherichia coli, which was successfully used to produce and purify inactive premersacidin. The purified product was used to determine the cleavage site of MrsT. Additionally, it was concluded from antimicrobial activity tests that in a second processing step mersacidin is activated by specific extracellular proteases from Bacillus amyloliquefaciens.

Original languageEnglish
Article numberacssynbio.0c00601
Pages (from-to)600-608
Number of pages9
JournalACS Synthetic Biology
Volume10
Issue number3
Early online date2021
DOIs
Publication statusPublished - Apr-2021

Keywords

  • mersacidin
  • lanthipeptides
  • RiPPs
  • leader processing
  • E. coli
  • heterologous expression
  • mutagenesis

Cite this