Bioinformatics-Guided Discovery of Biaryl-Tailored Lasso Peptides

Abstract

Lasso peptides are a class of ribosomally synthesized and post-translationally modified peptides (RiPPs) that feature an isopeptide bond and a distinct lariat fold. A growing number of secondary modifications have been described that further decorate lasso peptide scaffolds. Using genome mining, we have discovered a pair of lasso peptide biosynthetic gene clusters (BGCs) that include cytochrome P450 genes. Here, we report the structural characterization of two unique examples of (C-N) biaryl-containing lasso peptides. Nocapeptin A, from Nocardia terpenica, is tailored with Trp-Tyr crosslink while longipepetin A, from Longimycelium tulufanense, features Trp-Trp linkage. Besides the unusual bicyclic frame, longipepetin A receives an S-methylation by a new Met methyltransferase resulting in unprecedented sulfonium-bearing RiPP. Our bioinformatic survey revealed P450(s) and further maturating enzyme(s)-containing lasso BGCs awaiting future characterization.

Exploring the Diverse Landscape of Biaryl-Containing Peptides Generated by Cytochrome P450 Macrocyclases

“…The structural feature of lapparbin ( 3 ) is unique due to the presence of the Tyr C-6-to-Trp N-1′ linkage. To the best of our understanding, the chemical bond between Tyr C-6 and Trp N-1′ is very rare among natural products, while tryptorubins and nocapeptin A (Figure Q) display the similar C–N linkage in a reverse Trp-Tyr order. Therefore, the cyclic decapeptide ( 3 ) represents a new example of the unexplored natural chemical diversity generated by P450s.…”

Biosynthesis of Macrocyclic Peptides with C-Terminal β-Amino-α-keto Acid Groups by Three Different Metalloenzymes

“…The ribosomal precursor peptide frequently contains an N-terminal leader region typically responsible for recruiting the modifying enzymes, while a C-terminal core region receives the post-translational modifications . Exceptional transformations catalyzed by RiPP enzymes result in diverse structural moieties possessing antimicrobial, antiviral, antifungal, herbicidal, cytotoxic, anticancer, and other activities. − With nearly 50 reported structural classes, defined by the post-translational modification(s) (PTMs) installed, RiPP biosynthesis is a highly productive arena for the discovery of new enzyme chemistry, − identification of versatile bioengineering catalysts, − and isolation of structurally exotic compounds with unprecedented biological modes of action. , While tools like AlphaFold have provided high-quality structures for millions of enzymes, a major unsolved challenge is the determination of enzyme function. Typically, one does not know the substrate for a novel enzyme of interest .…”

Daropeptide natural products

“…In recent years, ribosomally synthesized and posttranslationally modified peptides (RiPPs) have emerged as a new source of naturally occurring peptide cyclophanes [7][8][9]. The cyclophane-containing RiPPs have been increasingly discovered in bacteria [10][11][12][13][14][15][16][17][18][19], fungi [20,21], and plants [22,23], and many of these compounds possess novel ring connectivity and topology that underpins equally diverse biological activities [24]. Moreover, these RiPP pathways offer a diverse set of cyclophane synthases that are dedicated biocatalysts for in trans polypeptide macrocyclization and are of important bioengineering application potential [25][26][27][28].…”