Summary While vegetative B acillus subtilis cells and mature spores are both surrounded by a thick layer of peptidoglycan ( PG , polymer glycan strands cross‐linked peptide bridges), it has remained unclear whether surrounds prespores during engulfment. To clarify this issue, we generated slender Δ ponA mutant that enabled high‐resolution electron cryotomographic imaging. Three‐dimensional reconstructions whole in near‐native states revealed thin ‐like extending from the lateral cell wall...

ABSTRACT Transcriptomic analyses during growth in Luria-Bertani medium were performed strain SL1344 of Salmonella enterica serovar Typhimurium and two isogenic derivatives lacking Dam methylase. More genes repressed than activated by methylation (139 versus 37). Key that differentially regulated verified independently. The largest classes Dam-repressed included belonging to the SOS regulon, as previously described Escherichia coli , SOS-inducible prophages ST64B, Gifsy-1, Fels-2....

The Gram-positive bacterium Bacillus subtilis can divide via two modes. During vegetative growth, the division septum is formed at midcell to produce equal daughter cells. However, during sporulation, closer one pole yield a smaller forespore and larger mother cell. Using cryo-electron tomography, genetics fluorescence microscopy, we found that organization of machinery different in septa. While FtsAZ filaments, major orchestrators bacterial cell division, are present uniformly around...

Increasing antimicrobial resistance has become a major public health crisis. New antimicrobials with novel mechanisms of action (MOA) are desperately needed. We previously developed method, bacterial cytological profiling (BCP), which utilizes fluorescence microscopy to rapidly identify the MOA compounds. BCP is based upon our discovery that cells treated antibiotics affecting different metabolic pathways generate signatures, providing quantitative information can be used determine...

When starved, the Gram-positive bacterium Bacillus subtilis forms durable spores for survival. Sporulation initiates with an asymmetric cell division, creating a large mother and small forespore. Subsequently, membrane engulfs forespore in phagocytosis-like process. However, force generation mechanism forward movement remains unknown. Here, we show that migration is driven by wall remodeling at leading edge of engulfing membrane, peptidoglycan synthesis degradation mediated penicillin...

Long 3′ untranslated regions (3′UTRs) are common in eukaryotic mRNAs. In contrast, long 3′UTRs rare bacteria, and have not been characterized detail. We describe a 3′UTR of 310 nucleotides hilD mRNA, transcript that encodes transcriptional activator Salmonella enterica pathogenicity island 1 (SPI-1). Deletion the increases mRNA level, suggesting may play role turnover. Cloning downstream green fluorescent protein (gfp) gene decreases (GFP) activity both Escherichia coli S. enterica,...

The study of bacterial cell biology is limited by difficulties in visualizing cellular structures at high spatial resolution within their native milieu. Here, we visualize Bacillus subtilis sporulation using cryo-electron tomography coupled with cryo-focused ion beam milling, allowing the reconstruction native-state sections molecular resolution. During sporulation, an asymmetrically-positioned septum generates a larger mother and smaller forespore. Subsequently, engulfs We show that septal...

Abstract DNA adenine methylase (Dam−) mutants of Salmonella enterica are attenuated in the mouse model and present multiple virulence-related defects. Impaired interaction Dam− with intestinal epithelium has been tentatively correlated reduced secretion pathogenicity island 1 (SPI-1) effectors. In this study, we show that S. contain lowered levels SPI-1 transcriptional regulators HilA, HilC, HilD, InvF. Epistasis analysis indicates Dam-dependent regulation requires while InvF dispensable. A...

SpoIIIE is a membrane-anchored DNA translocase that localizes to the septal midpoint mediate chromosome translocation and membrane fission during Bacillus subtilis sporulation. Here we use cell-specific protein degradation quantitative photoactivated localization microscopy in strains with thick sporulation septum investigate architecture function of complex vivo. We were able visualize complexes approximately equal numbers molecules mother cell forespore. Cell-specific showed only required...

Despite intensive research, the role of metabolism in bacterial sporulation remains poorly understood. Here, we demonstrate that Bacillus subtilis entails a marked metabolic differentiation two cells comprising sporangium: forespore, which becomes dormant spore, and mother cell, dies as completes. Our data provide evidence precursor biosynthesis restricted to cell forespore reliant on cell-derived metabolites for protein synthesis. We further show arginine is trafficked between proposed...

Bacillus subtilis sporulation entails a dramatic transformation of the two cells required to assemble dormant spore, with larger mother cell engulfing smaller forespore produce “cell within cell” structure that is hallmark endospore formation. Sporulation also metabolic differentiation, whereby key enzymes are depleted from but maintained in cell. This reduces potential forespore, which becomes dependent on metabolism and SpoIIQ–SpoIIIA channel obtain building blocks necessary for...

The damX gene product of Salmonella enterica serovar Typhimurium is a protein located in the inner membrane. DamX migrates as 70-kDa SDS-PAGE even though predicted size 46 kDa. Synthesis occurs both exponential- and stationary-phase cultures. Disruption causes severe sensitivity to bile. Lack outer membrane AsmA suppresses bile mutants.

Invasion of intestinal epithelial cells is a critical step in Salmonella infection and requires the expression genes located pathogenicity island 1 (SPI-1). A key factor for SPI-1 DNA adenine (Dam) methylation, which activates synthesis transcriptional activator HilD. Dam-dependent regulation hilD postranscriptional (and therefore indirect), indicating involvement unknown cell functions under Dam methylation control. genetic screen has identified std fimbrial operon as missing link between...

Summary In the model, heterocyst‐forming cyanobacterium Anabaena sp. PCC 7120, gene cluster alr2877‐alr2880 , which encodes an ABC‐type transport system, was induced under conditions of carbon limitation and its inactivation impaired uptake bicarbonate. Thus, this a Cmp bicarbonate transporter. ORF all0862 encoding LysR‐type transcriptional regulator, expressed at higher levels in absence than presence combined nitrogen, with positive effect N‐control transcription factor NtcA. from two...

Abstract Invasion of the intestinal epithelium is a critical step in Salmonella enterica infection and requires functions encoded gene cluster known as Pathogenicity Island 1 (SPI-1). Expression SPI-1 genes repressed by l-arabinose, not other pentoses. Transport l-arabinose necessary to repress SPI-1; however, repression independent metabolism l-arabinose-responsive regulator AraC. exerted at single target, HilD, mechanism appears be post-translational. As consequence repression, reduces...

To survive starvation, the bacterium Bacillus subtilis forms durable spores. The initial step of sporulation is asymmetric cell division, leading to a large mother-cell and small forespore compartment. After division completed dividing septum thinned, mother engulfs in slow process based on cell-wall degradation synthesis. However, recently new independent mechanism was shown significantly contribute, which can even lead fast engulfment 60 cases when wall completely removed. In this backup...

Understanding the mechanism of action (MOA) new antimicrobial agents is a critical step in drug discovery but notoriously difficult for compounds that appear to inhibit multiple cellular pathways. We recently described image-based approaches [bacterial cytological profiling and rapid inducible (RIP)] identifying pathways targeted by antibiotics. Here we have applied these methods examine effects proteolytically degrading enzymes involved pyrimidine nucleotide biosynthesis, pathway produces...

Summary Sporulation in Bacillus subtilis is a paradigm of bacterial development, which involves the interaction between larger mother cell and smaller forespore. The forespore activate different genetic programs, leading to production sporulation‐specific proteins. A critical gap our understanding sporulation how vegetative proteins, made before initiation, contribute spore formation. Here we present system, s patio t emporally r egulated p roteolysis (STRP), enables rapid, developmentally...

We recently showed that disruption of damX causes bile sensitivity in Salmonella enterica. The gene is part an operon contains genes with heterogeneous functions: DNA adenine methylation, biosynthesis aromatic compounds, carbohydrate metabolism, and tRNA charging. encodes a protein predicted size 46 kDa. In Salmonella, DamX found the inner membrane both dividing non-dividing cells. peptidoglycan-binding SPOR domain, accumulates E. coli septal ring. mutants lacking are bile-sensitive like...

Abstract Bacillus subtilis sporulation entails a dramatic transformation of the two cells required to assemble dormant spore, with larger mother cell engulfing smaller forespore produce cell-within-a-cell structure that is hallmark endospore formation. Sporulation also metabolic differentiation, whereby key enzymes are depleted from but maintained in cell. This reduces potential forespore, which becomes dependent on mother-cell metabolism and SpoIIQ-SpoIIIA channel obtain building blocks...