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[Identification and expression of plasmid genes participating in the synthesis of microcin C51]
Abstract:
A structural gene of heptapeptide, which is a component of the microcin C51 molecule, was identified by hybridization of plasmid DNA fragments and a mixture of synthesized oligonucleotides with the sequence corresponding to that of amino acids in the peptide. Sequence analysis of the structural gene of microcin peptide and its promoter region was performed. The data obtained indicate that the peptide of microcin C51 is synthesized on ribosomes. Four polypeptides of 67, 39, 16, and 14 kDa were identified using the system of minicells. These polypeptides are specified by a DNA fragment responsible for microcin synthesis and immunity in a producer cell. Apparently, three of these polypeptides with molecular masses of 67, 39, and 16 kDa are responsible for microcin production and immunity. The 67 kDa polypeptide is involved in the expression of immunity to microcin and, probably, in microcin production.
Insights
Researchers identified the structural gene for a heptapeptide in microcin C51. This peptide is ribosomally synthesized, and specific polypeptides are involved in microcin production and immunity.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Microcins are ribosomally synthesized peptides with antibiotic properties.
- Understanding the genetic basis of microcin production is crucial for developing novel antimicrobial agents.
Purpose of the Study:
- To identify and characterize the structural gene responsible for microcin C51 heptapeptide synthesis.
- To investigate the polypeptides involved in microcin C51 production and immunity.
Main Methods:
- Hybridization of plasmid DNA fragments with synthetic oligonucleotides.
- DNA sequence analysis of the microcin C51 structural gene and its promoter.
- Polypeptide identification using the minicell system.
Main Results:
- The structural gene for the microcin C51 heptapeptide was identified.
- Sequence analysis confirmed ribosomal synthesis of the microcin C51 peptide.
- Four polypeptides (67, 39, 16, and 14 kDa) were identified, with three (67, 39, and 16 kDa) implicated in microcin production and immunity.
Conclusions:
- The microcin C51 heptapeptide is ribosomally synthesized.
- A specific DNA fragment encodes polypeptides essential for microcin C51 production and host immunity.
- The 67 kDa polypeptide plays a key role in microcin immunity and production.