Identification of an Essential Gene of<i>Listeria monocytogenes</i>Involved in Teichoic Acid Biogenesis

Dubail, Iharilalao; Bigot, Armelle; Lazarević, Vladimir; Soldo, Blazenka; Euphrasie, Daniel; Dupuis, Marion; Charbit, Alain

doi:10.1128/jb.00771-06

Cited by 29 publications

(25 citation statements)

References 69 publications

(63 reference statements)

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“…However, our hmgR construct was able to grow in BHI broth without added IPTG, albeit to a lower extent than when IPTG was present. Our results are similar to those observed by Dubail et al (2006), who reported the first essential gene deletion in L. monocytogenes EGDe but found that there was sufficient gene expression (of lmo2537) from the IPTG promoter to support growth in the absence of the inducer. This demonstrates an essential requirement for hmgR in L. monocytogenes EGDe for in vitro growth, and suggests that low expression of the gene is sufficient to support growth.…”

Section: Discussionsupporting

confidence: 82%

HmgR, a key enzyme in the mevalonate pathway for isoprenoid biosynthesis, is essential for growth of Listeria monocytogenes EGDe

et al. 2012

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Section: Discussionsupporting

confidence: 82%

HmgR, a key enzyme in the mevalonate pathway for isoprenoid biosynthesis, is essential for growth of Listeria monocytogenes EGDe

et al. 2012

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“…It is possible that phage susceptibility could not be restored by complementation for these mutant strains because their respective mutations had a dominant effect over the respective WT allele; it is also possible that these mutations are not responsible for the observed phage resistance phenotype and that resistance is due to polar effects or other, nonidentified, mutations. However, lmo2537 (the LMRG_01710 homolog in 10403S) encodes UDP-N-acetylglucosamine 2-epimerase, which is a precursor of the teichoic acid linkage unit (61,62). This suggests that LMRG_01709 may have a direct effect on the composition of WTA and phage resistance as LMRG_01709 is part of the same operon as LMRG_01710; however, we cannot definitively exclude a polar effect on LMRG_01710.…”

Section: Discussionmentioning

confidence: 78%

“…In this study, WGS of 69 mutant strains enabled us to observe the parallel evolution of phage resistance in L. monocytogenes 10403S under the selective pressure of lytic phages, as evidenced by mutations repeatedly and independently occurring in the same genes and causing the same phenotypic effects. As WTA have been shown to be associated with virulence functions (71), including the evidence that a teichoic acid biosynthesis gene is essential for virulence of L. monocytogenes in mice (62), further studies to determine how the mutations found in this study affect virulence, as well as fitness, under a variety of different environmental and stress conditions will be valuable. Additional studies should also examine the frequency of occurrence and stability of the mutations identified here across different environmental conditions.…”

Section: Discussionmentioning

confidence: 99%

Selection and Characterization of Phage-Resistant Mutant Strains of Listeria monocytogenes Reveal Host Genes Linked to Phage Adsorption

Denes

Bakker

Tokman

et al. 2015

Appl Environ Microbiol

104

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Listeria-infecting phages are readily isolated from Listeria-containing environments, yet little is known about the selective forces they exert on their host. Here, we identified that two virulent phages, LP-048 and LP-125, adsorb to the surface of Listeria monocytogenes strain 10403S through different mechanisms. We isolated and sequenced, using whole-genome sequencing, 69 spontaneous mutant strains of 10403S that were resistant to either one or both phages. Mutations from 56 phage-resistant mutant strains with only a single mutation mapped to 10 genes representing five loci on the 10403S chromosome. An additional 12 mutant strains showed two mutations, and one mutant strain showed three mutations. Two of the loci, containing seven of the genes, accumulated the majority (n ‫؍‬ 64) of the mutations. A representative mutant strain for each of the 10 genes was shown to resist phage infection through mechanisms of adsorption inhibition. Complementation of mutant strains with the associated wild-type allele was able to rescue phage susceptibility for 6 out of the 10 representative mutant strains. Wheat germ agglutinin, which specifically binds to N-acetylglucosamine, bound to 10403S and mutant strains resistant to LP-048 but did not bind to mutant strains resistant to only LP-125. We conclude that mutant strains resistant to only LP-125 lack terminal N-acetylglucosamine in their wall teichoic acid (WTA), whereas mutant strains resistant to both phages have disruptive mutations in their rhamnose biosynthesis operon but still possess N-acetylglucosamine in their WTA. V irulent phages have been shown to present a tremendous selective pressure on their bacterial host populations. Not only is phage predation a major driver of bacterial diversification (1, 2), but it may also select for hypermutators, which could increase the frequency of mutations in bacterial populations (3, 4). Whereas bacteria are limited to one cell division per generation, a single phage-infected cell can produce a burst ranging from less than 5 to over 1,000 progeny phages in a similar period of time (5-7). Phages consequently have the capability to rapidly outgrow their bacterial hosts and can significantly reduce or eliminate susceptible bacteria in the local environment (8, 9). Therefore, the potential for bacterial strains to persist in an environment containing lytic phages may be contingent upon that strain accumulating spontaneous mutations that grant resistance to phage infection (10). These phage-resistant mutant strains most typically resist phage infection through mechanisms of adsorption inhibition, i.e., alterations of the cell surface that affect phage attachment (11). However, one study reported that nearly all phage-resistant mutant strains of Streptococcus thermophilus had acquired CRISPR spacers that matched invading phage genomes (12); these S. thermophilus mutant strains would be expected to resist phage infection after the adsorption step. Phage-resistant mutant strains that resist infection through mechanisms of adsorption inh...

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“…In addition to MurA and MurZ, there are three more UDP-GlcNAcconsuming enzymes present in L. monocytogenes (Fig. 6): (i) the essential MnaA protein (encoded by the lmo2537 gene) for the conversion of UDP-GlcNAc into UDP-N-acetylmannosamine, which is part of the teichoic acid linkage unit (26,27); (ii) the wall teichoic acid glycosylation protein GtcA (encoded by lmo2549) (28,29); and (iii) the glycosyltransferase encoded by the lmo2550 gene which is-as GtcAalso required for decoration of wall teichoic acids with GlcNAc (29). We assumed that-for the reasons described above-deletion of gtcA or lmo2550 possibly suppresses the ΔgpsB growth defects as well.…”

Section: Resultsmentioning

confidence: 99%

Suppressor Mutations LinkinggpsBwith the First Committed Step of Peptidoglycan Biosynthesis in Listeria monocytogenes

2017

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The cell division protein GpsB is a regulator of the penicillin binding protein A1 (PBP A1) in the Gram-positive human pathogen Listeria monocytogenes. Penicillin binding proteins mediate the last two steps of peptidoglycan biosynthesis as they polymerize and cross-link peptidoglycan strands, the main components of the bacterial cell wall. It is not known what other processes are controlled by GpsB. L. monocytogenes gpsB mutants are unable to grow at 42°C, but we observed that spontaneous suppressors correcting this defect arise on agar plates with high frequency. We here describe a first set of gpsB suppressors that mapped to the clpC and murZ genes. While ClpC is the ATPase component of the Clp protease, MurZ is a paralogue of the listerial UDP-N-acetylglucosamine (UDPGlcNAc) 1-carboxyvinyltransferase MurA. Both enzymes catalyze the enolpyruvyl transfer from phosphoenolpyruvate to UDP-GlcNAc, representing the first committed step of peptidoglycan biosynthesis. We confirmed that clean deletion of the clpC or murZ gene suppressed the ΔgpsB phenotype. It turned out that the absence of either gene leads to accumulation of MurA, and we show that artificial overexpression of MurA alone was sufficient for suppression. Inactivation of other UDP-GlcNAcconsuming pathways also suppressed the heat-sensitive growth of the ΔgpsB mutant, suggesting that an increased influx of precursor molecules into peptidoglycan biosynthesis can compensate for the lack of GpsB. Our results support a model according to which PBP A1 becomes misregulated and thus toxic in the absence of GpsB due to unproductive consumption of cell wall precursor molecules. IMPORTANCEThe late cell division protein GpsB is important for cell wall biosynthesis in Gram-positive bacteria. GpsB of the human pathogen L. monocytogenes interacts with one of the key enzymes of this pathway, penicillin binding protein A1 (PBP A1), and influences its activity. PBP A1 catalyzes the last two steps of cell wall biosynthesis, but it is unknown how GpsB controls PBP A1. We observed that a L. monocytogenes gpsB mutant forms spontaneous suppressors and have mapped their mutations to genes mediating and influencing the first step of cell wall biosynthesis, likely stimulating the influx of metabolites into this pathway. We assume that GpsB is important to ensure productive incorporation of cell wall precursors into the peptidoglycan sacculus by PBP A1.KEYWORDS GpsB, MurA, UDP-N-acetylglucosamine, PBP A1, peptidoglycan, UDP-N-acetylglucosamine T he cell wall represents the outmost layer of the bacterial envelope in Gram-positive bacteria. It confers rigidity and shape to their cells and provides a platform for incorporation of many molecules, e.g., proteins and wall teichoic acids, which need to be presented on the bacterial surface (1-3). The Gram-positive cell wall consists of a

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Identification of an Essential Gene ofListeria monocytogenesInvolved in Teichoic Acid Biogenesis

Cited by 29 publications

References 69 publications

HmgR, a key enzyme in the mevalonate pathway for isoprenoid biosynthesis, is essential for growth of Listeria monocytogenes EGDe

HmgR, a key enzyme in the mevalonate pathway for isoprenoid biosynthesis, is essential for growth of Listeria monocytogenes EGDe

Selection and Characterization of Phage-Resistant Mutant Strains of Listeria monocytogenes Reveal Host Genes Linked to Phage Adsorption

Suppressor Mutations LinkinggpsBwith the First Committed Step of Peptidoglycan Biosynthesis in Listeria monocytogenes

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