[Microcin R51 and a plasmid determining its synthesis].

Area of Science:

• Microbiology
• Bacteriology
• Molecular Biology

Context:

• A novel microcin antibiotic, designated microcin R51, has been identified from the Citrobacter R51 strain.
• This microcin exhibits broad-spectrum antibacterial activity against both Gram-negative and Gram-positive bacteria in minimal medium.
• The synthesis of microcin R51 is constitutively regulated and linked to a conjugative plasmid.

Purpose:

• To characterize the properties of the newly detected microcin.
• To investigate the genetic basis of microcin R51 synthesis and immunity.
• To clone and physically map the genes responsible for microcin R51 production and resistance.

Summary:

• A new microcin antibiotic from Citrobacter R51 was detected and partially purified.
• Its constitutive synthesis is controlled by a conjugative plasmid.
• Genes for microcin R51 synthesis and immunity were cloned, and a physical map of the 12 kb fragment was generated.

Impact:

• Provides insights into the mechanisms of microcin production and regulation.
• Facilitates further research into novel antibiotic development.
• Contributes to the understanding of plasmid-mediated antibiotic resistance and synthesis.