Discovery of Streptomyces Umbrella Toxin Particles that Inhibit Growth of Competing Bacterial Species

Conceptos Básicos

Streptomyces bacteria produce and secrete large protein complexes called "umbrella particles" that act as potent toxins to inhibit the growth of competing Streptomyces species, a function distinct from small-molecule antibiotics.

Resumen

The content describes the discovery of a novel antibacterial mechanism employed by Streptomyces bacteria, a ubiquitous genus of soil bacteria that produce the majority of clinically used antibiotics. In addition to small-molecule antibiotics, Streptomyces species also produce and secrete large protein complexes called "umbrella particles" that act as potent toxins to inhibit the growth of competing Streptomyces species.
The key highlights are:

Streptomyces umbrella particles are large, degenerate repeat-containing polymorphic toxin protein complexes with an extended stalk topped by a ringed crown comprising the toxin repeats scaffolding five lectin-tipped spokes.
Streptomyces coelicolor encodes three distinct umbrella particles with different toxin and lectin compositions.
Supernatant containing these umbrella particles specifically and potently inhibits the growth of select Streptomyces species, but not a diverse collection of other bacteria.
For the target species Streptomyces griseus, the inhibition relies on a single toxin and manifests as rapid cessation of vegetative hyphal growth.
Sequence analyses suggest that the role of umbrella particles in mediating competition among Streptomyces species extends beyond this genus, as similar loci were identified in nearly 1,000 species across Actinobacteria.
This antibacterial function of umbrella particles is distinct from small-molecule antibiotics, which are produced at the onset of reproductive growth and act more broadly.

Estadísticas

Streptomyces bacteria produce the majority of clinically used antibiotics.
Streptomyces coelicolor encodes three distinct umbrella particles with different toxin and lectin compositions.
Umbrella particle loci were identified in nearly 1,000 species across Actinobacteria.

Citas

"Streptomyces are a genus of ubiquitous soil bacteria from which the majority of clinically utilized antibiotics derive1."
"Our data show that Streptomyces umbrella particles mediate competition among vegetative mycelia of related species, a function distinct from small-molecule antibiotics, which are produced at the onset of reproductive growth and act broadly3,4."

Ideas clave extraídas de

Streptomyces umbrella toxin particles block hyphal growth of competing species - Nature

by Qinqin Zhao,... a las www.nature.com 04-17-2024

https://www.nature.com/articles/s41586-024-07298-z

Consultas más profundas

What are the potential applications of Streptomyces umbrella particles in the development of novel antimicrobial therapies?

The discovery of Streptomyces umbrella particles opens up exciting possibilities for the development of novel antimicrobial therapies. These particles, with their unique structure and composition, offer a targeted approach to combating bacterial infections. By specifically inhibiting the growth of select Streptomyces species, umbrella particles could be harnessed to create highly effective and selective antimicrobial agents. This targeted action could potentially reduce the development of resistance, a major concern in the field of antibiotics. Furthermore, the identification of umbrella loci in a wide range of Actinobacteria species suggests that these particles could serve as a broad-spectrum antimicrobial therapy, effective against a diverse array of bacterial pathogens.

How do the distinct toxin and lectin compositions of the three umbrella particles in Streptomyces coelicolor contribute to their specific inhibition of different Streptomyces species?

The distinct toxin and lectin compositions of the three umbrella particles in Streptomyces coelicolor play a crucial role in their specific inhibition of different Streptomyces species. Each umbrella particle contains a unique combination of toxins and lectins, which interact with specific targets on the surface of the target bacteria. This specificity allows the umbrella particles to selectively inhibit the growth of particular Streptomyces species while leaving others unaffected. By targeting key components of the competing species, such as the vegetative hyphal growth in Streptomyces griseus, the umbrella particles effectively disrupt the growth and proliferation of these bacteria. This targeted approach enhances the efficiency and efficacy of the umbrella particles as antimicrobial agents.

What evolutionary pressures and ecological factors have driven the widespread distribution of umbrella particle loci across the Actinobacteria phylum?

The widespread distribution of umbrella particle loci across the Actinobacteria phylum can be attributed to evolutionary pressures and ecological factors that have shaped the survival strategies of these bacteria. Actinobacteria, including Streptomyces, inhabit diverse environments where competition for resources is intense. The production of umbrella particles, with their ability to inhibit the growth of competing species, confers a competitive advantage to Actinobacteria in these environments. Through the evolution of umbrella loci, Actinobacteria have developed a sophisticated mechanism to outcompete other bacteria and secure their access to essential nutrients. This evolutionary adaptation has driven the widespread distribution of umbrella particle loci across the Actinobacteria phylum, highlighting the importance of inter-species competition in shaping microbial communities.