Characterization of a chromosomally encoded glycylglycine endopeptidase of Staphylococcus aureus

Ramadurai, Lakshmi; Lockwood, Katherine J.; Lockwood, John W.; Nadakavukaren, Mathew J.; Jayaswal, Radheshyam K.

doi:10.1099/13500872-145-4-801

Cited by 77 publications

(97 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The C-terminal domains of the four proteins belong to COG4942 (membrane-bound metallopeptidases, involved in cell division and chromosome partitioning) and are characteristic for members of the M23/M37 family (Pfam01551) of putative zinc metalloendopeptidases from Gram-negative and Gram-positive bacteria (http://www.sanger.ac.uk/Software/Pfam/). The M37 protease family includes staphylococcal glycylglycine endopeptidases that hydrolyse the polyglycine interpeptide bridges of peptidoglycan of Gram-positive bacteria (Ramadurai & Jayaswal, 1997;Ramadurai et al, 1999;Recsei et al, 1987;Sugai et al, 1997) and the E. coli lipoprotein Fig. 7.…”

Section: Discussionmentioning

confidence: 99%

The amoebae plate test implicates a paralogue of lpxB in the interaction of Legionella pneumophila with Acanthamoeba castellanii

et al. 2005

View full text Add to dashboard Cite

Legionella pneumophila is a bacterial parasite of freshwater amoebae which also grows in alveolar macrophages and thus causes the potentially fatal pneumonia Legionnaires' disease. Intracellular growth within amoebae and macrophages is mechanistically similar and requires the Icm/Dot type IV secretion system. This paper reports the development of an assay, the amoebae plate test (APT), to analyse growth of L. pneumophila wild-type and icm/dot mutant strains spotted on agar plates in the presence of Acanthamoeba castellanii. In the APT, wild-type L. pneumophila formed robust colonies even at high dilutions, icmT, -R, -P or dotB mutants failed to grow, and icmS or -G mutants were partially growth defective. The icmS or icmG mutant strains were used to screen an L. pneumophila chromosomal library for genes that suppress the growth defect in the presence of the amoebae. An icmS suppressor plasmid was isolated that harboured the icmS and flanking icm genes, indicating that this plasmid complements the intracellular growth defect of the mutant. In contrast, different icmG suppressor plasmids rendered the icmG mutant more cytotoxic for A. castellanii without enhancing intracellular multiplication in amoebae or RAW264.7 macrophages. Deletion of individual genes in the suppressor plasmids inserts identified lcs (Legionella cytotoxic suppressor) -A, -B, -C and -D as being required for enhanced cytotoxicity of an icmG mutant strain. The corresponding proteins show sequence similarity to hydrolases, NlpD-related metalloproteases, lipid A disaccharide synthases and ABC transporters, respectively. Overexpression of LcsC, a putative paralogue of the lipid A disaccharide synthase LpxB, increased cytotoxicity of an icmG mutant but not that of other icm/dot or rpoS mutant strains against A. castellanii. Based on sequence comparison and chromosomal location, lcsB and lcsC probably encode enzymes involved in cell wall maintenance and peptidoglycan metabolism. The APT established here may prove useful to identify other bacterial factors relevant for interactions with amoeba hosts.

show abstract

Section: Discussionmentioning

confidence: 99%

The amoebae plate test implicates a paralogue of lpxB in the interaction of Legionella pneumophila with Acanthamoeba castellanii

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Although not studied in S. aureus, phosphate transport systems have been shown to be important for cwrA responds to cell wall damage the modification of lipopolysaccharides, outer-membrane proteins and membrane lipids, which in turn mediate resistance to different host defence elements that target the bacterial cell surface (Lamarche et al, 2008). Additionally, lytM, encoding a gly-gly endopeptidase (Ramadurai et al, 1999), and sceD, encoding a lytic transglycosylase (Stapleton et al, 2007), both involved in cell wall turnover, were upregulated twofold in the cwrA knockout.…”

Section: Generation Of Cwra Knockouts and Transcriptional Profilingmentioning

confidence: 99%

cwrA, a gene that specifically responds to cell wall damage in Staphylococcus aureus

Balibar¹,

Shen²,

McGuire³

et al. 2010

Microbiology

View full text Add to dashboard Cite

Transcriptional profiling data accumulated in recent years for the clinically relevant pathogen Staphylococcus aureus have established a cell wall stress stimulon, which comprises a coordinately regulated set of genes that are upregulated in response to blockage of cell wall biogenesis. In particular, the expression of cwrA (SA2343, N315 notation), which encodes a putative 63 amino acid polypeptide of unknown biological function, increases over 100-fold in response to cell wall inhibition. Herein, we seek to understand the biological role that this gene plays in S. aureus. cwrA was found to be robustly induced by all cell wall-targeting antibiotics tested – vancomycin, oxacillin, penicillin G, phosphomycin, imipenem, hymeglusin and bacitracin – but not by antibiotics with other mechanisms of action, including ciprofloxacin, erythromycin, chloramphenicol, triclosan, rifampicin, novobiocin and carbonyl cyanide 3-chlorophenylhydrazone. Although a ΔcwrA S. aureus strain had no appreciable shift in MICs for cell wall-targeting antibiotics, the knockout was shown to have reduced cell wall integrity in a variety of other assays. Additionally, the gene was shown to be important for virulence in a mouse sepsis model of infection.

show abstract

“…This finding correlates well with the observation that the levels of LytM drop considerably during stationary growth phase. 53 Probing the structure of the large mRNA revealed that the RBS could form alternative basepairing interactions with upstream nucleotides located in the 5 0 UTR to occlude ribosome binding. In vitro translation assays suggested that the synthesis of LytM is not coupled to SA0264 and that the bicistronic operon generates a translationally inactive lytM mRNA (Fig.…”

Section: Discussionmentioning

confidence: 99%

Various checkpoints prevent the synthesis ofStaphylococcus aureuspeptidoglycan hydrolase LytM in the stationary growth phase

et al. 2016

View full text Add to dashboard Cite

In Staphylococcus aureus, peptidoglycan metabolism plays a role in the host inflammatory response and pathogenesis. Transcription of the peptidoglycan hydrolases is activated by the essential 2-component system WalKR at low cell density. During stationary growth phase, WalKR is not active and transcription of the peptidoglycan hydrolase genes is repressed. In this work, we studied regulation of expression of the glycylglycine endopeptidase LytM. We show that, in addition to the transcriptional regulation mediated by WalKR, the synthesis of LytM is negatively controlled by a unique mechanism at the stationary growth phase. We have identified 2 different mRNAs encoding lytM, which vary in the length of their 5 0 untranslated (5 0 UTR) regions. LytM is predominantly produced from the WalKR-regulated mRNA transcript carrying a short 5 0 UTR. The lytM mRNA is also transcribed as part of a polycistronic operon with the upstream SA0264 gene and is constitutively expressed. Although SA0264 protein can be synthesized from the longer operon transcript, lytM cannot be translated because its ribosome-binding site is sequestered into a translationally inactive secondary structure. In addition, the effector of the agr system, RNAIII, can inhibit translation of lytM present on the operon without altering the transcript level but does not have an effect on the translation of the upstream gene. We propose that this dual regulation of lytM expression, at the transcriptional and post-transcriptional levels, contributes to prevent cell wall damage during the stationary phase of growth.

show abstract

Characterization of a chromosomally encoded glycylglycine endopeptidase of Staphylococcus aureus

Cited by 77 publications

References 33 publications

The amoebae plate test implicates a paralogue of lpxB in the interaction of Legionella pneumophila with Acanthamoeba castellanii

The amoebae plate test implicates a paralogue of lpxB in the interaction of Legionella pneumophila with Acanthamoeba castellanii

cwrA, a gene that specifically responds to cell wall damage in Staphylococcus aureus

Various checkpoints prevent the synthesis ofStaphylococcus aureuspeptidoglycan hydrolase LytM in the stationary growth phase

Contact Info

Product

Resources

About