RiPP recognition elements evolved to prevent pathway interference through leader peptide discrimination

Area of Science:

• Biochemistry
• Molecular Biology
• Natural Product Discovery

Background:

• Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a diverse class of natural products.
• RiPP biosynthesis often involves specific interactions between precursor peptides and adapter proteins like RiPP recognition elements (RREs).
• The co-localization of RiPP and lasso peptide gene clusters in Bacillota suggests potential pathway conflicts.

Purpose of the Study:

• To investigate a newly discovered family of RiPPs found in Bacillota genomes.
• To understand the molecular mechanisms enabling the coexistence of distinct RiPP biosynthetic pathways, specifically RiPPs and lasso peptides.
• To elucidate the evolutionary strategies employed by these systems to avoid pathway interference.

Main Methods:

• Bioinformatic analysis of RiPP biosynthetic gene clusters in Bacillota.
• Biochemical assays to study protein-peptide interactions.
• Structural biology techniques to determine key molecular interactions.

Main Results:

• Discovery of a widespread family of RiPPs in Bacillota, often co-localizing with lasso peptides.
• Identification of conserved RRE-binding motifs on precursor peptides.
• Biochemical and structural data revealing how cognate recognition and discrimination between precursor peptides and leader peptidases are achieved.
• Demonstration of mechanisms allowing the coexistence of two RiPP biosynthetic systems within a single host.

Conclusions:

• The discovered RiPP family possesses unique evolutionary adaptations for cohabitation with other RiPPs, such as lasso peptides.
• Specific molecular interactions and discrimination mechanisms prevent cross-reactivity between related biosynthetic pathways.
• This study enhances our understanding of RiPP evolution and the diversification of natural product biosynthesis.