Biosynthetic Gene Clusters in Streptomyces Genomics

Streptomyces bacteria are renowned for their capacity to synthesise a vast array of secondary metabolites, many of which underpin modern antibiotics, antifungals and anticancer agents. These compounds are encoded by biosynthetic gene clusters (BGCs), discrete genomic loci that assemble multimodular enzymes such as polyketide synthases and non-ribosomal peptide synthetases. The linear chromosomes of Streptomyces species typically harbour 20–60 BGCs, with core housekeeping genes concentrated centrally and rapidly evolving secondary-metabolite clusters enriched towards the terminal arms. Advances in long-read sequencing and genome mining have revealed extensive strain-level diversity and frequent chromosomal rearrangements, which contribute to the activation or silencing of BGCs. Integrative approaches combining comparative genomics, epigenetic profiling and synthetic biology now enable rational cluster activation, heterologous expression and chassis engineering. These efforts are critical to combat antimicrobial resistance, expand chemical diversity and unlock cryptic natural products for biotechnology and drug discovery.

Research from Nature Portfolio

Recent studies have employed large-scale genome mining across more than a thousand Streptomyces genomes to chart the diversity and distribution of major BGC classes. This work demonstrated high phylogenetic variability even among closely related strains, emphasising the need for strain-specific exploration. It also revealed that operational taxonomic units defined by 16S rRNA may mask profound chemical and genomic diversity, with identical ribosomal markers sometimes corresponding to distinct secondary-metabolite repertoires. These findings underscore the importance of whole-genome analyses for accurate prioritisation of novel clusters and highlight limitations of single-gene taxonomy in natural-product discovery.

Biosynthetic Gene Clusters in Streptomyces Genomics publication trend

The graph below shows the total number of articles in biosynthetic gene clusters in streptomyces genomics across all publications each year (not limited to Nature Index journals).

Technical terms

Biosynthetic gene cluster (BGC): A contiguous set of genes that encode enzymes and regulatory proteins responsible for the production of a specific secondary metabolite.

Polyketide synthase (PKS): A modular, multi-domain enzyme complex that catalyses the assembly of polyketide backbones via successive condensation of acyl-CoA precursors.

Non-ribosomal peptide synthetase (NRPS): A large enzyme system that assembles peptide products independently of the ribosome, often incorporating non-proteinogenic amino acids.

Linear chromosome: A chromosome with two ends rather than a closed circular structure, characteristic of Streptomyces, featuring terminal inverted repeats and specialised replication mechanisms.

Terminal inverted repeats (TIRs): Highly conserved, inverted sequences at the ends of a linear chromosome that play roles in replication and genome stability.

Silent gene cluster: A BGC that is present in the genome but not actively expressed under standard laboratory conditions, often requiring elicitors or genetic rewiring for activation.

References

1. A treasure trove of 1034 actinomycete genomes. Nucleic Acids Research (2024).
2. Oxytetracycline hyper-production through targeted genome reduction of Streptomyces rimosus. mSystems (2024).
3. A panoramic view of the genomic landscape of the genus Streptomyces. Microbial Genomics (2023).
4. Multiple Streptomyces species with distinct secondary metabolomes have identical 16S rRNA gene sequences. Scientific Reports (2017).