Gene-Encoded Antibiotics Made in Bacteria

  1. Joan Marsh Organizer and
  2. Jamie A. Goode
  1. Hans-Georg Sahl

Published Online: 28 SEP 2007

DOI: 10.1002/9780470514658.ch3

Ciba Foundation Symposium 186 - Antimicrobial Peptides

Ciba Foundation Symposium 186 - Antimicrobial Peptides

How to Cite

Sahl, H.-G. (2007) Gene-Encoded Antibiotics Made in Bacteria, in Ciba Foundation Symposium 186 - Antimicrobial Peptides (eds J. Marsh and J. A. Goode), John Wiley & Sons, Ltd., Chichester, UK. doi: 10.1002/9780470514658.ch3

Author Information

  1. Institut für Medizinische Mikrobiologie und Immunologie der Universität Bonn, Sigmund Freund Strasse 25, D-53105 Bonn, Germany

Publication History

  1. Published Online: 28 SEP 2007

ISBN Information

Print ISBN: 9780471950257

Online ISBN: 9780470514658

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Keywords:

  • gram-negative bacteria;
  • lantibiotic gene;
  • cell wall-degrading;
  • escherichia coli;
  • gyrase inhibitor

Summary

Production of antimicrobial peptides and proteins is very common among bacteria and a variety of such substances has been described. In general Gram-negative bacteria produce protein bacteriocins (e.g. colicins) with narrow action spectra based on receptor-mediated activity. They produce comparatively few peptides, such as the post-translationally modified microcin B17. In contrast Gram-positive bacteria tend to produce peptide bacteriocins smaller than 10 kDa and of wider activity spectra. These show particular potential for application. They can be divided into unmodified peptides (e.g. lactococcins, lactacins, pediocins) and lanthionine-containing peptides (lantibiotics, e.g. nisin, epidermin, Pep5). The unmodified peptides are mostly hydrophobic or amphiphilic and act by disturbing the function of the cytoplasmic membrane. They are synthesized as prepeptides with a characteristic N-terminal leader peptide. In some cases genes for immunity peptides were found in close proximity to structural genes; furthermore, two-component response regulators seem to be involved in the regulation of their synthesis. The biosynthetic genes for lantibiotics are also organized in operons. Lantibiotic gene clusters include genes encoding the unique enzymes which dehydrate serine and threonine and form the characteristic thioether-bridged lanthionines. Three types of lantibiotics are currently distinguished on the basis of structural features and functional aspects: type A, which include elongated, amphiphilic, pore-forming peptides (e.g. nisin); type B, which are of globular shape and inhibit phospholipases (e.g. duramycins); and type C (e.g. actagardine) with intermediate features which act by inhibiting bacterial cell wall biosynthesis.