Related Experiment Video
Updated: Jun 26, 2026
11:56
Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids
Published on: May 4, 2018
Structure-function relationships of the non-lanthionine-containing peptide (class II) bacteriocins produced by
J Nissen-Meyer1, P Rogne, C Oppegård
1Department of Molecular Biosciences, University of Oslo, Oslo, Norway. jon.nissen-meyer@imbv.uio.no
Current Pharmaceutical Biotechnology
|January 20, 2009
Summary
This review details non-lanthionine-containing peptide bacteriocins from Gram-positive bacteria. These cationic peptides kill cells by permeabilizing membranes, often by targeting specific membrane proteins.
Area of Science:
- Microbiology
- Biochemistry
- Structural Biology
Background:
- Non-lanthionine-containing peptide bacteriocins are antimicrobial peptides produced by Gram-positive bacteria.
- These bacteriocins play a role in bacterial competition and defense.
Purpose of the Study:
- To review the structure and mode-of-action of non-lanthionine-containing peptide bacteriocins.
- To categorize these bacteriocins into distinct structural and functional groups.
Main Methods:
- Literature review of existing studies on bacteriocin structure and function.
- Analysis of structural data, including X-ray crystallography and NMR spectroscopy.
- Comparison of mechanisms of action across different bacteriocin groups.
Main Results:
- Bacteriocins are classified into four groups: pediocin-like, two-peptide, cyclic, and linear non-pediocin-like.
- These cationic peptides (20-70 residues) primarily kill cells via membrane permeabilization.
- Pediocin-like bacteriocins interact with the mannose phosphotransferase permease, causing membrane leakage.
Conclusions:
- A common mechanism of action involves membrane penetration and binding to integrated membrane proteins, leading to cell death.
- Structural insights into two-peptide bacteriocins suggest helix-helix interactions within cell membranes.
- Immunity proteins protect producer cells by inhibiting bacteriocin-induced membrane leakage.
More Related Videos
06:05Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins
Published on: September 30, 2014
10:13Production and Visualization of Bacterial Spheroplasts and Protoplasts to Characterize Antimicrobial Peptide Localization
Published on: August 11, 2018
Related Concept Videos
01:23Inhibitors of Gram-positive Cell Wall Synthesis
Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
01:17Gram-negative Bacterial Protein Secretion Systems
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
01:12Bacterial Toxins
Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
01:29Cytoskeletal Proteins in Bacteria
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
01:28Peptidoglycan Synthesis
Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. It consists of repeating units of two sugars—N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)—linked by β-1,4 glycosidic bonds. These sugar chains are cross-linked by short peptide chains, forming a mesh-like polymer that surrounds the bacterial plasma membrane.Cytoplasmic Phase – Precursor SynthesisPeptidoglycan biosynthesis begins in...
01:26Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...