Article

Bacterial peptidoglycan degrading enzymes and their impact on host muropeptide detection.

University of Colorado, Denver, Colo, USA.
Journal of Innate Immunity (Impact Factor: 4.56). 02/2009; 1(2):88-97. DOI: 10.1159/000181181
Source: PubMed

ABSTRACT Peptidoglycan (PGN) is a major component of the bacterial cell envelope in both Gram-positive and Gram-negative bacteria. These muropeptides can be produced or modified by the activity of bacterial glycolytic and peptidolytic enzymes referred to as PGN hydrolases and autolysins. Some of these bacterial enzymes are crucial for bacterial pathogenicity and have been shown to modulate muropeptide release and/or host innate immune responses. The ability of muropeptides to modulate host responses is due to the fact that eukaryotes do not produce PGN and have instead evolved numerous strategies to detect intact PGN and PGN fragments (muropeptides). Here we review the structure of PGN and introduce the various bacterial enzymes known to degrade or modify bacterial PGN. Host factors involved in PGN and muropeptide detection are also briefly discussed, as are examples of how specific bacterial pathogens use PGN degradation and modification to subvert host innate immunity.

3 Followers
 · 
222 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Endolysins belonging to the group of peptigoglycan hydrolases, which are able to cleave peptidoglycan in bacterial cell walls, become an extensively studied group of enzymes. Thanks to their narrow target specificity and low probability of resistance they are considered to be an appropriate alternative to conventional antibiotics. The present paper concerns the occurrence of endolysin and endolysin-like genes in genomes of bacteria belonging to the order Lactobacillales. Using bioinformatic programmes we compared and analysed protein sequences of catalytic and cell wall binding (CWB) domains of these enzymes, their preferred combinations, their phylogenetic relationship and potential occurence of natural "domain shuffling". The existence of this phenomenon in selected group of enzymes was confirmed only in limited range, so we assume that the natural trend is the distribution of "well-tried" combinations of catalytic and CWB domains of endolysin genes as a whole.
    06/2012; 11(1). DOI:10.2478/v10296-012-0001-4
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Intracellular Chlamydiaceae do not need to resist osmotic challenges and a functional cell wall was not detected in these pathogens. Nevertheless, a recent study revealed evidence for circular peptidoglycan-like structures in Chlamydiaceae and penicillin inhibits cytokinesis, a phenomenon known as the chlamydial anomaly. Here, by characterizing a cell wall precursor-processing enzyme, we provide insights into the mechanisms underlying this mystery. We show that AmiA from Chlamydia pneumoniae separates daughter cells in an Escherichia coli amidase mutant. Contrary to homologues from free-living bacteria, chlamydial AmiA uses lipid II as a substrate and has dual activity, acting as an amidase and a carboxypeptidase. The latter function is penicillin sensitive and assigned to a penicillin-binding protein motif. Consistent with the lack of a regulatory domain in AmiA, chlamydial CPn0902, annotated as NlpD, is a carboxypeptidase, rather than an amidase activator, which is the case for E. coli NlpD. Functional conservation of AmiA implicates a role in cytokinesis and host response modulation.
    Nature Communications 06/2014; 5:4201. DOI:10.1038/ncomms5201 · 10.74 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Staphylococcus aureus is a major human and animal pathogen. Autolysins regulate the growth, turnover, cell lysis, biofilm formation, and the pathogenicity of S. aureus. Atl is the major autolysin in S. aureus. The biochemical and structural studies of staphylococcal Atl have been limited due to difficulty in cloning, high level overexpression, and purification of this protein. This study describes successful cloning, high level over-expression, and purification of two forms of fully functional Atl proteins. These pure proteins can be used to study the functional and structural properties of this important protein.
    International Journal of Microbiology 01/2014; 2014:615965. DOI:10.1155/2014/615965

Preview

Download
3 Downloads
Available from