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Pep5, a new lantibiotic: structural gene isolation and prepeptide sequence
C Kaletta1, K D Entian, R Kellner
1Institut für Mikrobiologie, Universität Frankfurt, Federal Republic of Germany.
Archives of Microbiology
|January 1, 1989
Summary
Researchers identified the lantibiotic Pep5 gene (pepA) on plasmid pED503 using a synthetic oligonucleotide probe. This confirms Pep5 is ribosomally synthesized and reveals details about its prepeptide structure and maturation process.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Lantibiotics are ribosomally synthesized peptides with antimicrobial properties.
- Pep5 is a lantibiotic whose genetic basis and maturation pathway were previously uncharacterized.
Purpose of the Study:
- To identify and characterize the structural gene (pepA) for the lantibiotic Pep5.
- To elucidate the ribosomal synthesis and maturation process of Pep5.
Main Methods:
- Oligonucleotide probe design based on the Pep5 propeptide sequence.
- Hybridization screening to locate the pepA gene on plasmid pED503.
- Nucleotide sequencing of the pepA gene.
Main Results:
- The structural gene pepA was identified on the 18.6 kbp plasmid pED503.
- Nucleotide sequencing revealed pepA codes for a 60-residue prepeptide, confirming ribosomal synthesis.
- The prepeptide N-terminus exhibits alpha-helix probability, with a cleavage site preceding the 34-residue propeptide.
Conclusions:
- Pep5 is confirmed to be ribosomally synthesized.
- The maturation of Pep5 likely involves enzymatic modification of amino acids and proteolytic cleavage.
- A model for Pep5 maturation includes dehydration, sulfide bridge formation, translocation, and cleavage.