Genomics‐Driven Discovery of a Novel Glutarimide Antibiotic from <i>Burkholderia gladioli</i> Reveals an Unusual Polyketide Synthase Chain Release Mechanism

Nakou, Ioanna T.; Jenner, Matthew; Dashti, Yousef; Romero‐Canelón, Isolda; Masschelein, Joleen; Mahenthiralingam, Eshwar; Challis, Gregory L.

doi:10.1002/ange.202009007

Cited by 7 publications

(4 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spt2-spt3 and spt6-spt9 gene fusions are similar to recently described multi-domain enzyme fusions in the desferrioxamine (des) BGC, where they are hypothesized to contribute to chemical diversification [96]. Two additional fusions involving an AfsA/Spt9 homologue were observed within trans-AT PKS modules associated with gladiofungin and gladiostatin biosynthesis, where AfsA functions for unprecedented offloading and butenolide formation [97,98]. Identifying unusual gene fusions such as these represents an exciting new avenue for genome-mining-driven natural product discovery [96,99].…”

Section: Discussionsupporting

confidence: 70%

Phylogenetic analysis of the salinipostin γ-butyrolactone gene cluster uncovers new potential for bacterial signalling-molecule diversity

et al. 2021

View full text Add to dashboard Cite

Bacteria communicate by small-molecule chemicals that facilitate intra- and inter-species interactions. These extracellular signalling molecules mediate diverse processes including virulence, bioluminescence, biofilm formation, motility and specialized metabolism. The signalling molecules produced by members of the phylum Actinobacteria generally comprise γ-butyrolactones, γ-butenolides and furans. The best-known actinomycete γ-butyrolactone is A-factor, which triggers specialized metabolism and morphological differentiation in the genus Streptomyces . Salinipostins A–K are unique γ-butyrolactone molecules with rare phosphotriester moieties that were recently characterized from the marine actinomycete genus Salinispora . The production of these compounds has been linked to the nine-gene biosynthetic gene cluster (BGC) spt. Critical to salinipostin assembly is the γ-butyrolactone synthase encoded by spt9. Here, we report the surprising distribution of spt9 homologues across 12 bacterial phyla, the majority of which are not known to produce γ-butyrolactones. Further analyses uncovered a large group of spt-like gene clusters outside of the genus Salinispora , suggesting the production of new salinipostin-like diversity. These gene clusters show evidence of horizontal transfer and location-specific recombination among Salinispora strains. The results suggest that γ-butyrolactone production may be more widespread than previously recognized. The identification of new γ-butyrolactone BGCs is the first step towards understanding the regulatory roles of the encoded small molecules in Actinobacteria.

show abstract

Section: Discussionsupporting

confidence: 70%

Phylogenetic analysis of the salinipostin γ-butyrolactone gene cluster uncovers new potential for bacterial signalling-molecule diversity

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Genome mining suggests that various bacterial taxa have recruited AfsA-like domains to be used in thiotemplate systems. As it is complementary to currently known avenues, [18d, 21] the chain-termination mechanism employed by the gla PKS [22] opens new possibilities for synthetic biology approaches. In this context, CRISPR/Cas genome editing of Burkholderia was established to enable the precise, marker-less alteration of a megasynthase.…”

Section: Angewandte Chemiementioning

confidence: 99%

Insect‐Associated Bacteria Assemble the Antifungal Butenolide Gladiofungin by Non‐Canonical Polyketide Chain Termination

et al. 2020

View full text Add to dashboard Cite

Genome mining of one of the protective symbionts (Burkholderia gladioli) of the invasive beetle Lagria villosa revealed a cryptic gene cluster that codes for the biosynthesis of a novel antifungal polyketide with a glutarimide pharmacophore. Targeted gene inactivation, metabolic profiling, and bioassays led to the discovery of the gladiofungins as previously-overlooked components of the antimicrobial armory of the beetle symbiont, which are highly active against the entomopathogenic fungus Purpureocillium lilacinum. By mutational analyses, isotope labeling, and computational analyses of the modular polyketide synthase, we found that the rare butenolide moiety of gladiofungins derives from an unprecedented polyketide chain termination reaction involving a glycerol-derived C3 building block. The key role of an Afactor synthase (AfsA)-like offloading domain was corroborated by CRISPR-Cas-mediated gene editing, which facilitated precise excision within a PKS domain.

show abstract

“…The gdsB gene in the gladiostatin biosynthetic gene cluster in B. gladioli BCC1622 encodes a protein predicted to contain acyl hydrolase (AH), AT, and ER domains. 34 The ER domain of GdsB shares 57% sequence identity with GbnE. A double knockout mutant of B. gladioli BCC1622, containing in frame deletions in both gbnE and the ER domain of gdsB was therefore created (Figure S5).…”

Section: Resultsmentioning

confidence: 99%

Antibiotic skeletal diversification via differential enoylreductase recruitment and module iteration intrans-acyltransferase polyketide synthases

Jian,

Pang,

Hobson

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Microorganisms are remarkable chemists capable of assembling complex molecular architectures that penetrate cells and bind biomolecular targets with exquisite selectivity. Consequently, microbial natural products have wide-ranging applications in medicine and agriculture. How the “blind watchmaker” of evolution creates skeletal diversity is a key question in contemporary natural products research. Comparative analysis of biosynthetic pathways to structurally related metabolites is an insightful approach to addressing this.Here we report comparative biosynthetic investigations of gladiolin, a polyketide antibiotic fromBurkholderia gladioliwith promising activity against multidrug resistantMycobacterium tuberculosis, and entangien, a structurally related antibiotic produced bySorangium cellulosum. Although these metabolites have very similar macrolide cores, their C21 side chains differ significantly in both length and degree of saturation. Surprisingly, thetrans-acyltransferase polyketide synthases (PKSs) that assemble these antibiotics are almost identical, raising intriguing questions about mechanisms underlying structural diversification in this important class of biosynthetic assembly line.In vitro reconstitution of key biosynthetic transformations using simplified substrate analogues, combined with gene deletion and complementation experiments, enabled us to elucidate the origin of all structural differences in the C21 side chains of gladiolin and etnangien. The more saturated gladiolin side chain arises from a cis-acting enoylreductase (ER) domain in module 1 and in trans recruitment of a standalone ER to module 5 of the PKS. Remarkably, module 5 of the gladiolin PKS is intrinsically iterative in the absence of the standalone ER, accounting for the longer side chain in etnangien. These findings have important implications for biosynthetic engineering approaches to the creation of novel polyketide skeletons.

show abstract

Genomics‐Driven Discovery of a Novel Glutarimide Antibiotic from Burkholderia gladioli Reveals an Unusual Polyketide Synthase Chain Release Mechanism

Cited by 7 publications

References 42 publications

Phylogenetic analysis of the salinipostin γ-butyrolactone gene cluster uncovers new potential for bacterial signalling-molecule diversity

Phylogenetic analysis of the salinipostin γ-butyrolactone gene cluster uncovers new potential for bacterial signalling-molecule diversity

Insect‐Associated Bacteria Assemble the Antifungal Butenolide Gladiofungin by Non‐Canonical Polyketide Chain Termination

Antibiotic skeletal diversification via differential enoylreductase recruitment and module iteration intrans-acyltransferase polyketide synthases

Contact Info

Product

Resources

About