scholarly journals Precursor-centric genome-mining approach for lasso peptide discovery

2012 ◽  
Vol 109 (38) ◽  
pp. 15223-15228 ◽  
Author(s):  
Mikhail O. Maksimov ◽  
István Pelczer ◽  
A. James Link

Lasso peptides are a class of ribosomally synthesized posttranslationally modified natural products found in bacteria. Currently known lasso peptides have a diverse set of pharmacologically relevant activities, including inhibition of bacterial growth, receptor antagonism, and enzyme inhibition. The biosynthesis of lasso peptides is specified by a cluster of three genes encoding a precursor protein and two enzymes. Here we develop a unique genome-mining algorithm to identify lasso peptide gene clusters in prokaryotes. Our approach involves pattern matching to a small number of conserved amino acids in precursor proteins, and thus allows for a more global survey of lasso peptide gene clusters than does homology-based genome mining. Of more than 3,000 currently sequenced prokaryotic genomes, we found 76 organisms that are putative lasso peptide producers. These organisms span nine bacterial phyla and an archaeal phylum. To provide validation of the genome-mining method, we focused on a single lasso peptide predicted to be produced by the freshwater bacterium Asticcacaulis excentricus. Heterologous expression of an engineered, minimal gene cluster in Escherichia coli led to the production of a unique lasso peptide, astexin-1. At 23 aa, astexin-1 is the largest lasso peptide isolated to date. It is also highly polar, in contrast to many lasso peptides that are primarily hydrophobic. Astexin-1 has modest antimicrobial activity against its phylogenetic relative Caulobacter crescentus. The solution structure of astexin-1 was determined revealing a unique topology that is stabilized by hydrogen bonding between segments of the peptide.

2021 ◽  
Author(s):  
Li Cao ◽  
Moshe Beiser ◽  
Joseph D Koos ◽  
Margarita Orlova ◽  
Hader E Elashal ◽  
...  

Lasso peptides are a family of ribosomally synthesized and post-translationally modified peptides (RiPPs) defined by their threaded structure. Besides the class-defining isopeptide bond, other post-translational modifications (PTMs) that further tailor lasso peptides have been previously reported. Using genome mining tools, we identified a subset of lasso peptide biosynthetic gene clusters (BGCs) that are colocalized with protein L-isoaspartyl methyltransferase (PIMT) homologs. PIMTs have an important role in protein repair, restoring isoaspartate residues formed from asparagine deamidation to aspartate. Here we report a new function for PIMT enzymes in the post-translational modification of lasso peptides. The PIMTs associated with lasso peptide BGCs first methylate an L-aspartate sidechain found within the ring of the lasso peptide. The methyl ester is then converted into a stable aspartimide moiety, endowing the lasso peptide ring with rigidity relative to its unmodified counterpart. We describe the heterologous expression and structural characterization of two examples of aspartimide-modified lasso peptides from thermophilic Gram-positive bacteria. The lasso peptide cellulonodin-2 is encoded in the genome of actinobacterium Thermobifida cellulosilytica, while lihuanodin is encoded in the genome of firmicute Lihuaxuella thermophila. Additional genome mining revealed PIMT-containing lasso peptide BGCs in 48 organisms. In addition to heterologous expression, we have reconstituted PIMT-mediated aspartimide formation in vitro, showing that lasso peptide-associated PIMTs transfer methyl groups very rapidly as compared to canonical PIMTs. Furthermore, in stark contrast to other characterized lasso peptide PTMs, the methyltransferase functions only on lassoed substrates.


2021 ◽  
Author(s):  
Lydia Stariha ◽  
Dewey G. McCafferty

<p>Lasso peptides are a structurally diverse superfamily of</p><p>conformationally-constrained peptide natural products, of which a</p><p>subset exhibits broad antimicrobial activity. Although advances in</p><p>bioinformatics have increased our knowledge of strains harboring</p><p>the biosynthetic machinery for lasso peptide production, relating</p><p>peptide sequence to bioactivity remains a continuous challenge.</p><p>Towards this end, a structure-driven genome mining investigation</p><p>of Actinobacteria-produced antimicrobial lasso peptides was</p><p>performed to correlate predicted primary structure with antibiotic</p><p>activity. Bioinformatic evaluation revealed eight putative novel</p><p>class I lasso peptide sequences. This subset is predicted to</p><p>possess antibiotic activity as characterized members of this class</p><p>have both broad spectrum and potent activity against Gram positive</p><p>strains. Fermentation of one of these hits, Streptomyces</p><p>NRRL F-5639, resulted in the production of a novel class I lasso</p><p>peptide, arcumycin, named for the Latin word for bow or arch,</p><p>arcum. Arcumycin exhibited antibiotic activity against Gram positive</p><p>bacteria including <i>Bacillus subtilis</i> (4 μg/mL),</p><p><i>Staphylococcus aureus </i>(8 μg/mL), and <i>Micrococcus luteus</i> (8</p><p>μg/mL). Arcumycin treatment of <i>B. subtilis</i> liaI-β-gal promoter</p><p>fusion reporter strain resulted in upregulation of the system liaRS</p><p>by the promoter liaI, indicating arcumycin interferes with lipid II</p><p>biosynthesis. Cumulatively, the results illustrate the relationship</p><p>between phylogenetically related lasso peptides and their</p><p>bioactivity as validated through the isolation, structural</p><p>determination, and evaluation of bioactivity of the novel class I</p><p>antimicrobial lasso peptide arcumycin.</p>


2019 ◽  
Vol 85 (23) ◽  
Author(s):  
Juan Pablo Gomez-Escribano ◽  
Jean Franco Castro ◽  
Valeria Razmilic ◽  
Scott A. Jarmusch ◽  
Gerhard Saalbach ◽  
...  

ABSTRACT Analysis of the genome sequence of Streptomyces leeuwenhoekii C34T identified biosynthetic gene clusters (BGCs) for three different lasso peptides (Lp1, Lp2, and Lp3) which were not known to be made by the strain. Lasso peptides represent relatively new members of the RiPP (ribosomally synthesized and posttranslationally modified peptides) family of natural products and have not been extensively studied. Lp3, whose production could be detected in culture supernatants from S. leeuwenhoekii C34T and after heterologous expression of its BGC in Streptomyces coelicolor, is identical to the previously characterized chaxapeptin. Lp1, whose production could not be detected or achieved heterologously, appears to be identical to a recently identified member of the citrulassin family of lasso peptides. Since production of Lp2 by S. leeuwenhoekii C34T was not observed, its BGC was also expressed in S. coelicolor. The lasso peptide was isolated and its structure confirmed by mass spectrometry and nuclear magnetic resonance analyses, revealing a novel structure that appears to represent a new family of lasso peptides. IMPORTANCE Recent developments in genome sequencing combined with bioinformatic analysis have revealed that actinomycetes contain a plethora of unexpected BGCs and thus have the potential to produce many more natural products than previously thought. This reflects the inability to detect the production of these compounds under laboratory conditions, perhaps through the use of inappropriate growth media or the absence of the environmental cues required to elicit expression of the corresponding BGCs. One approach to overcoming this problem is to circumvent the regulatory mechanisms that control expression of the BGC in its natural host by deploying heterologous expression. The generally compact nature of lasso peptide BGCs makes them particularly amenable to this approach, and, in the example given here, analysis revealed a new member of the lasso peptide family of RiPPs. This approach should be readily applicable to other cryptic lasso peptide gene clusters and would also facilitate the design and production of nonnatural variants by changing the sequence encoding the core peptide, as has been achieved with other classes of RiPPs.


Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 20
Author(s):  
Tiago Leão ◽  
Mingxun Wang ◽  
Nathan Moss ◽  
Ricardo da Silva ◽  
Jon Sanders ◽  
...  

Microbial natural products are important for the understanding of microbial interactions, chemical defense and communication, and have also served as an inspirational source for numerous pharmaceutical drugs. Tropical marine cyanobacteria have been highlighted as a great source of new natural products, however, few reports have appeared wherein a multi-omics approach has been used to study their natural products potential (i.e., reports are often focused on an individual natural product and its biosynthesis). This study focuses on describing the natural product genetic potential as well as the expressed natural product molecules in benthic tropical cyanobacteria. We collected from several sites around the world and sequenced the genomes of 24 tropical filamentous marine cyanobacteria. The informatics program antiSMASH was used to annotate the major classes of gene clusters. BiG-SCAPE phylum-wide analysis revealed the most promising strains for natural product discovery among these cyanobacteria. LCMS/MS-based metabolomics highlighted the most abundant molecules and molecular classes among 10 of these marine cyanobacterial samples. We observed that despite many genes encoding for peptidic natural products, peptides were not as abundant as lipids and lipopeptides in the chemical extracts. Our results highlight a number of highly interesting biosynthetic gene clusters for genome mining among these cyanobacterial samples.


2021 ◽  
Author(s):  
Nadia Eusebio ◽  
Adriana Rego ◽  
Nathaniel R. Glasser ◽  
Raquel Castelo-Branco ◽  
Emily P. Balskus ◽  
...  

AbstractHalogenation is a recurring feature in natural products, especially those from marine organisms. The selectivity with which halogenating enzymes act on their substrates renders halogenases interesting targets for biocatalyst development. Recently, CylC – the first predicted dimetal-carboxylate halogenase to be characterized – was shown to regio- and stereoselectively install a chlorine atom onto an unactivated carbon center during cylindrocyclophane biosynthesis. Homologs of CylC are also found in other characterized cyanobacterial secondary metabolite biosynthetic gene clusters. Due to its novelty in biological catalysis, selectivity and ability to perform C-H activation, this halogenase class is of considerable fundamental and applied interest. However, little is known regarding the diversity and distribution of these enzymes in bacteria. In this study, we used both genome mining and PCR-based screening to explore the genetic diversity and distribution of CylC homologs. While we found non-cyanobacterial homologs of these enzymes to be rare, we identified a large number of genes encoding CylC-like enzymes in publicly available cyanobacterial genomes and in our in-house culture collection of cyanobacteria. Genes encoding CylC homologs are widely distributed throughout the cyanobacterial tree of life, within biosynthetic gene clusters of distinct architectures. Their genomic contexts feature a variety of biosynthetic partners, including fatty-acid activation enzymes, type I or type III polyketide synthases, dialkylresorcinol-generating enzymes, monooxygenases or Rieske proteins. Our study also reveals that dimetal-carboxylate halogenases are among the most abundant types of halogenating enzymes in the phylum Cyanobacteria. This work will help to guide the search for new halogenating biocatalysts and natural product scaffolds.Data statementAll supporting data and methods have been provided within the article or through a Supplementary Material file, which includes 14 supplementary figures and 4 supplementary tables.


2020 ◽  
Author(s):  
Yuanyuan Si ◽  
Ashley M. Kretsch ◽  
Laura M. Daigh ◽  
Mark J. Burk ◽  
Douglas A. Mitchell

AbstractLasso peptides are ribosomally synthesized and post-translationally modified peptide (RiPP) natural products that display a unique lariat-like structure. Owing to a rigid topology, lasso peptides are unusually stable towards heat and proteolytic degradation. Some lasso peptides have been shown to bind human cell-surface receptors and exhibit anticancer properties, while others display antibacterial or antiviral activities. Known lasso peptides are produced by bacteria and genome-mining studies indicate that lasso peptides are a relatively prevalent RiPP class; however, the discovery, isolation, and characterization of lasso peptides are constrained by the lack of an efficient production system. In this study, we employ a cell-free biosynthesis (CFB) strategy to address the longstanding challenges associated with lasso peptide production. We report the successful formation of a diverse array of lasso peptides that include known examples as well as a new predicted lasso peptide from Thermobifida halotolerans. We further demonstrate the utility of CFB to rapidly generate and characterize multisite precursor peptide variants in order to evaluate the substrate tolerance of the biosynthetic pathway. We show that the lasso-forming cyclase from the fusilassin pathway can produce millions of sequence-diverse lasso peptides via CFB with an extraordinary level of sequence permissiveness within the ring region of the lasso peptide. These data lay a firm foundation for the creation of large lasso peptide libraries using CFB to identify new variants with unique properties.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Nadia Eusebio ◽  
Adriana Rego ◽  
Nathaniel R. Glasser ◽  
Raquel Castelo-Branco ◽  
Emily P. Balskus ◽  
...  

Abstract Background Halogenation is a recurring feature in natural products, especially those from marine organisms. The selectivity with which halogenating enzymes act on their substrates renders halogenases interesting targets for biocatalyst development. Recently, CylC – the first predicted dimetal-carboxylate halogenase to be characterized – was shown to regio- and stereoselectively install a chlorine atom onto an unactivated carbon center during cylindrocyclophane biosynthesis. Homologs of CylC are also found in other characterized cyanobacterial secondary metabolite biosynthetic gene clusters. Due to its novelty in biological catalysis, selectivity and ability to perform C-H activation, this halogenase class is of considerable fundamental and applied interest. The study of CylC-like enzymes will provide insights into substrate scope, mechanism and catalytic partners, and will also enable engineering these biocatalysts for similar or additional C-H activating functions. Still, little is known regarding the diversity and distribution of these enzymes. Results In this study, we used both genome mining and PCR-based screening to explore the genetic diversity of CylC homologs and their distribution in bacteria. While we found non-cyanobacterial homologs of these enzymes to be rare, we identified a large number of genes encoding CylC-like enzymes in publicly available cyanobacterial genomes and in our in-house culture collection of cyanobacteria. Genes encoding CylC homologs are widely distributed throughout the cyanobacterial tree of life, within biosynthetic gene clusters of distinct architectures (combination of unique gene groups). These enzymes are found in a variety of biosynthetic contexts, which include fatty-acid activating enzymes, type I or type III polyketide synthases, dialkylresorcinol-generating enzymes, monooxygenases or Rieske proteins. Our study also reveals that dimetal-carboxylate halogenases are among the most abundant types of halogenating enzymes in the phylum Cyanobacteria. Conclusions Our data show that dimetal-carboxylate halogenases are widely distributed throughout the Cyanobacteria phylum and that BGCs encoding CylC homologs are diverse and mostly uncharacterized. This work will help guide the search for new halogenating biocatalysts and natural product scaffolds.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 588
Author(s):  
Kunjukrishnan Kamalakshi Sivakala ◽  
Karina Gutiérrez-García ◽  
Polpass Arul Jose ◽  
Thangadurai Thinesh ◽  
Rangasamy Anandham ◽  
...  

Searching for new bioactive metabolites from the bacterial genus Streptomyces is a challenging task. Combined genomic tools and metabolomic screening of Streptomyces spp. native to extreme environments could be a promising strategy to discover novel compounds. While Streptomyces of desertic origin have been proposed as a source of new metabolites, their genome mining, phylogenetic analysis, and metabolite profiles to date are scarcely documented. Here, we hypothesized that Streptomyces species of desert environments have evolved with unique biosynthetic potential. To test this, along with an extensive characterization of biosynthetic potential of a desert isolate Streptomyces sp. SAJ15, we profiled phylogenetic relationships among the closest and previously reported Streptomyces of desert origin. Results revealed that Streptomyces strains of desert origin are closer to each other and relatively distinct from Streptomyces of other environments. The draft genome of strain SAJ15 was 8.2 Mb in size, which had 6972 predicted genes including 3097 genes encoding hypothetical proteins. Successive genome mining and phylogenetic analysis revealed the presence of putative novel biosynthetic gene clusters (BGCs) with low incidence in another Streptomyces. In addition, high-resolution metabolite profiling indicated the production of arylpolyene, terpenoid, and macrolide compounds in an optimized medium by strain SAJ15. The relative abundance of different BGCs in arid Streptomyces differed from the non-arid counterparts. Collectively, the results suggested a distinct evolution of desert Streptomyces with a unique biosynthetic potential.


Marine Drugs ◽  
2020 ◽  
Vol 18 (5) ◽  
pp. 238 ◽  
Author(s):  
Daniel Oves-Costales ◽  
Marina Sánchez-Hidalgo ◽  
Jesús Martín ◽  
Olga Genilloud

RES-701-3 and RES-701-4 are two class II lasso peptides originally identified in the fermentation broth of Streptomyces sp. RE-896, which have been described as selective endothelin type B receptor antagonists. These two lasso peptides only differ in the identity of the C-terminal residue (tryptophan in RES-701-3, 7-hydroxy-tryptophan in RES-701-4), thus raising an intriguing question about the mechanism behind the modification of the tryptophan residue. In this study, we describe the identification of their biosynthetic gene cluster through the genome mining of the marine actinomycete Streptomyces caniferus CA-271066, its cloning and heterologous expression, and show that the seven open reading frames (ORFs) encoded within the gene cluster are sufficient for the biosynthesis of both lasso peptides. We propose that ResE, a protein lacking known putatively conserved domains, is likely to play a key role in the post-translational modification of the C-terminal tryptophan of RES-701-3 that affords RES-701-4. A BLASTP search with the ResE amino acid sequence shows the presence of homologues of this protein in the genomes of eight other Streptomyces strains, which also harbour the genes encoding the RES-701-3, -4 precursor peptide, split-B proteins and ATP-dependent lactam synthetase required for the biosynthesis of these compounds.


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Ema Damayanti ◽  
Jaka Widada ◽  
Achmad Dinoto ◽  
Mustofa

High resistance to chloroquine in most malaria-endemic area in the world leads to the need for new antimalaria drugs. Marine bacterium Streptomyces  is the source for potential new antimalarial molecules. This research aimed to investigate antiplasmodial activity of marine-derived of Streptomyces sp. GMY01 and to identify potential active compounds using genome mining study. In vitro antiplasmodial activity assays using flow cytometry method showed that the ethyl acetate extract of this bacterium had high antiplasmodial activity (IC50 value of 1.183 µg/mL) on Plasmodium falciparum FCR3. Genome mining analysis of whole-genome sequences using antiSMASH 6.0 beta version revealed that Streptomyces sp. GMY01 had 28 biosynthetic gene clusters (BGCs), including the genes encoding polyketide synthase, non-ribosomal peptide synthetase, terpene, lanthipeptide, bacteriocin, butyrolactone, ectoin, siderophore, and others. The known BGCs were predicted to be involved in the production of known compounds from gene clusters ranged from 5 to 100% similarity. Ongoing purification and elucidation of the structures will allow identification of the active compounds produced by marine-derived Streptomyces sp. GMY01.


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