Biology subjects

Eswara, P. J.

Publications and source records attributed to Eswara, P. J..

14 recordsLinked to original sources

bioRxiv2026

Staphylococcus aureus GpsB, Stk, and VraSR form a cell wall surveillance network to maintain cell envelope integrity and mediate antibiotic resistance

Antibiotic resistance is an alarming threat to public health worldwide. Specifically, drug-resistant Staphylococcus aureus remains a major contributor to global mortality. Therefore, in-depth understanding of antibiotic resistance mechanisms is urgently needed to inform alternative therapeutic strategies. We previously showed that GpsB is a critical regulator of cell wall synthesis in S. aureus. GpsB executes its regulatory role via protein-protein interactions. Yet, how GpsB function is modulated in this organism has remained unclear. Intriguingly, a prior proteomics report indicated that GpsB is phosphorylated at six different residues by the sole serine/threonine kinase Stk. Hence, we explored the physiological significance of GpsB phosphorylation. We identify three phosphosites that are each independently sufficient to drive GpsB phosphoregulation, which likely alters its partner preference. We find that cells lacking gpsB exhibit heightened fosfomycin sensitivity, and that this is exacerbated by stk deletion. Our findings reveal that GpsB collaborates with Stk and the VraSR cell wall stress response system to coordinate the demand-driven availability of cell wall precursors. Collectively, this report establishes GpsB as a pivotal peptidoglycan supply chain sentinel that together with Stk and VraSR forms an integrated cell wall stress monitoring network that maintains cell envelope homeostasis and aids in antibiotic resistance.

microbiology↗

bioRxiv2026

Magnesium induces iron starvation and metabolic rewiring to support the viability of cell envelope mutants and antibiotic-stressed cells

Magnesium supplementation permits deletion of otherwise essential genes involved in cell envelope biogenesis in the Gram-positive model bacterium Bacillus subtilis. Yet, the specific underlying mechanism has remained elusive. To address this key knowledge gap, we made use of a mutant lacking ezrA and gpsB. Deletion of both of these genes involved in cell wall synthesis leads to severe growth inhibition which is ameliorated by magnesium addition. Our results indicate that, in the absence of magnesium, this mutant contains elevated levels of labile iron, is impaired in activating the oxidative stress response, and displays extreme sensitivity to iron and manganese intoxication. Intriguingly, we find that an ezrA single deletion, but not gpsB, exhibits heightened susceptibility to excess iron and manganese. This observation allowed us to investigate the source of toxicity and how EzrA may support metal homeostasis. Our data suggests that the major contributor of ROS is the electron transport system involved in cellular respiration. Both genetic and chemical means to reprogram the cells in favor of fermentation alleviate the metal toxicity in cells lacking ezrA. Collectively, our data shows that magnesium limits iron availability and redirects metabolism towards pathways that are preferred during iron scarcity. Consequently, these mechanisms result in reduced ROS production and oxidative stress mitigation. This explains why magnesium supplementation may render essential genes dispensable. In support of this model, we find that addition of magnesium helps cells to circumvent lysis typically caused by the treatment of an antibiotic that disrupts cell wall synthesis. Taken together, our results suggest that unmitigated oxidative stress fueled by labile iron is likely responsible for the detrimental effects of specific gene disruptions and certain antibiotic treatments. By reducing the pool of free iron and reprogramming cellular metabolism, magnesium mitigates oxidative damage and protects cells from ROS-mediated death.

microbiology↗

bioRxiv2026

Shedding light on YfhS and YjlC: novel effectors of the NADH dehydrogenase activity of the electron transport chain in Bacillus subtilis

Oxidative phosphorylation is the most efficient way of generating ATP in respiring cells. As high energy electrons are the major source of reactive oxygen species their production needs to be carefully calibrated. In most organisms, NADH dehydrogenase serves as the primary source and gateway of electrons. This complex is responsible for oxidizing NADH to NAD+, which liberates two electrons that are then fed into the respiratory chain. In the Gram-positive model bacterium, Bacillus subtilis, a transcription factor (Rex) is utilized to monitor the rise in NADH level and subsequently increase the production of the NADH dehydrogenase Ndh. Thus, the generation of electrons through this pathway is tightly regulated. In this report, we reveal the presence of another independent mechanism to moderate Ndh activity involving a previously uncharacterized protein, YfhS. Additionally, we present the first experimental evidence showing that the functional NADH dehydrogenase is a two-protein complex comprised of a membrane-associated YjlC and the enzyme Ndh. We find that absence of YfhS leads to cell morphology and growth defects that are corrected by spontaneous mutations in ndh. We note that increased production of NADH dehydrogenase complex proteins by itself is not detrimental. However, strikingly, it is lethal in a strain lacking yfhS. These results reveal that YfhS is an important moderator of NADH dehydrogenase activity. We also demonstrate that YfhS and YjlC are interaction partners. A model developed based on our data indicates that YfhS is an important regulator of intracellular NADH concentration. Compounds that target specific microbial (Type II) NADH dehydrogenase, which is absent in human mitochondria, are considered promising drug candidates to help address the threat posed by antibiotic-resistant bacteria. Overall, our data unveiling the importance of YfhS and YjlC in controlling Ndh activity could be harnessed for the development of new therapeutics.

microbiology↗

bioRxiv2025

Staying in the loop to make ends meet: roles and regulation of GlmR in Bacillus subtilis

The metabolic networks of most life forms integrate cost-benefit analysis to properly budget carbon and other essential nutrients through continuous assessment of nutrient availability and environmental threats. Bacillus subtilis is a Gram-positive model bacterium found in diverse ecological niches such as soil, marine environments, and the human gut. As such, B. subtilis cells finetune metabolic pathways by monitoring signals indicating the presence of nutrients and stressors. A highly conserved protein, GlmR, is a key player in rationing carbon for the production of cell envelope precursors. This function of GlmR can be attributed to its role in cell shape regulation and antibiotic resistance. Given its central position in carbon utilization, GlmR is under post-translational regulation by phosphorylation and UDP-N-acetylglucosamine (UDP-GlcNAc) binding. GlmR is also linked to cyclic-di-AMP (c-di-AMP), a nucleotide second messenger involved in stress response. In this study, we probed the importance of GlmR in cell morphogenesis, c-di-AMP signaling, and investigated the physiological significance of post-translational regulation. Our results reveal that cells lacking glmR exhibit: (i) increased susceptibility to tunicamycin, a cell envelope targeting antibiotic; (ii) impaired division site positioning; and (iii) elevated intracellular c-di-AMP concentration. Furthermore, we show that the function of GlmR is finetuned by UDP-GlcNAc binding, phosphorylation, and acetylation. Additionally, we provide evidence showing that the recently discovered enzymatic activity of GlmR is integral for its function. We show that GlmR is a cell width determinant and propose a model suggesting close cooperation with an actin-like protein, MreB. Overall, our studies highlight that GlmR is at the crux of carbon flux with an important role in maintaining cell envelope integrity. IMPORTANCEBacteria must integrate feedback from multiple metabolic processes to efficiently allocate carbon to produce essential building blocks such as nucleotides, amino acids, and cell wall precursors to support life. GlmR is a critical metabolic factor involved in the making of cell envelope precursors in diverse bacterial phyla. In Bacillus subtilis, cells lacking GlmR are deformed and hypersensitive to cell wall targeting antibiotics. As siphoning off too much carbon from other essential processes is detrimental to cell viability, GlmR activity is tightly regulated. Here we report that absence of GlmR leads to aberrant placement of cytokinetic machinery and an increase in the levels of cyclic-di-AMP, a nucleotide second messenger that assists in the cell wall stress response. We also show that GlmR function is post-translationally finetuned by phosphorylation and acetylation. Furthermore, our data reveals that the catalytic activity of GlmR is required for its function. Thus, the activity of GlmR is tightly calibrated through multiple means for efficient carbon utilization.

microbiology↗

bioRxiv2024

GpsB is an accessory Z-ring anchor

Bacterial cytokinesis is a well-coordinated process in which multiple proteins, collectively called the divisome, are recruited to the site of division. A key member of the divisome is FtsZ which forms a ring-like structure (Z-ring) to mark the division site through its association with Z-ring anchors. Synchronized movement of Z-ring filaments and peptidoglycan synthesis along the axis of division help generate a division septum to separate the daughter cells. Thus, FtsZ needs to be linked to the PG synthesis machinery. GpsB is a highly conserved protein among the members of the Firmicutes phylum which has been shown to regulate cell wall synthesis through interaction with penicillin binding proteins. Previously published data from our lab established GpsB as a member of the divisome which directly interacts with FtsZ in Staphylococcus aureus. More specifically, we showed that GpsB binds to FtsZ by recognizing the R-X-X-R sequence in its C- terminal tail (CTT) region. As the GpsB recognition sequence is also present in Bacillus subtilis, we speculated that GpsB-FtsZ interaction might occur in this organism as well. In support of our prediction, previous studies reported that disruption of gpsB and ezrA or gpsB and ftsA is deleterious. Given that both EzrA and FtsA are known Z-ring anchors, we hypothesized that in the absence of other FtsZ anchors, GpsB can fulfill this role in B. subtilis. Our data, taken together, conclusively shows that GpsB is a Z-ring anchor in B. subtilis and this role of GpsB only becomes apparent in the absence of other FtsZ anchoring proteins. Based on the conserved nature of the R-X-X-R sequence in FtsZ- CTT, we also tested GpsB-FtsZ interaction in Enterococcus faecalis and Listeria monocytogenes and show that this recognition motif dependent interaction is present in the former but not the latter. Our results suggest the possibility of C-terminal R-X-X-R independent interaction in L. monocytogenes and Streptococcus pneumoniae. Thus, it appears that GpsB may serve as an accessory Z-ring anchor in multiple organisms. ImportanceCell division is essential for production of offsprings and propagation of life. In bacteria, a key tubulin-like cell division protein FtsZ is brought to the division site by the action of multiple regulators. Arrival of FtsZ and activation of cell wall synthesis are needed to build a division septum to separate the daughter cells. As such, this vital process is controlled by redundant fail-safe mechanisms. For instance, multiple proteins can anchor FtsZ to the membrane at the division site. In this report, we reveal that yet another protein, GpsB, could serve as a back-up FtsZ anchor. GpsB is normally associated with cell wall synthesis in most organisms of the Firmicutes phylum. However, in the absence of other known dedicated FtsZ anchoring factors, GpsB is able to step in to rescue cell division. We provide evidence that this GpsB-FtsZ interaction is present in Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis, Listeria monocytogenes, and possibly Streptococcus pneumoniae. As the rapid rise in antibiotic resistance is threatening public health globally, knowledge of unique important cell division factors could be harnessed to develop new antibacterial therapeutics.

microbiology↗

bioRxiv2022

Staphylococcus aureus FtsZ and PBP4 bind to the conformationally dynamic N-terminal domain of GpsB

Bacterial cell division is a tightly regulated process that requires the formation of a dynamic multi-protein complex. In the Firmicutes phylum, GpsB is a membrane associated protein that coordinates peptidoglycan synthesis for cell growth and division. Although GpsB has been studied in several organisms, the structure, function, and interactome of Staphylococcus aureus GpsB is largely uncharacterized, despite being reported as uniquely essential for growth in this clinically relevant bacterium. To address this knowledge gap, we solved the crystal structure of the N-terminal domain of S. aureus GpsB. This structure reveals an atypical asymmetric dimer, and major conformational flexibility that can be mapped to a hinge region formed by a three-residue insertion exclusive to Staphylococci. When this three-residue insertion is excised, its thermal stability increases, and the mutant no longer produces a previously reported lethal phenotype when overexpressed in Bacillus subtilis. Furthermore, we provide the first biochemical, biophysical, and crystallographic evidence that the N-terminal domain of GpsB binds not only PBP4, but also FtsZ, through a conserved recognition motif located on their C-terminus, thus linking peptidoglycan synthesis with cell division. Taken together, the unique structure of S. aureus GpsB and its direct interaction with FtsZ/PBP4 provide deeper insight into the central role of GpsB in S. aureus cell division.

microbiology↗

bioRxiv2022

Bacterial threat assessment of bacteriophage infection is mediated by intracellular polyamine accumulation and Gac/Rsm signaling

When eukaryotic cells are killed by pathogenic microorganisms, damage-associated and pathogen-associated signals are generated that alert other cells of nearby danger. Bacteria can detect the death of their kin; however, how bacteria make threat assessments of cellular injury is largely unexplored. Here we show that polyamines released by lysed bacteria serve as damage-associated molecules in Pseudomonas aeruginosa. In response to exogenous polyamines, Gac/Rsm and cyclic-di-GMP signaling is activated and intracellular polyamine levels increase. In the absence of a threat, polyamines are catabolized, and intracellular polyamines return to basal levels, but cells infected by bacteriophage increase and maintain intracellular polyamine levels, which inhibits phage replication. Phage species not inhibited by polyamines did not trigger polyamine accumulation by P. aeruginosa, suggesting polyamine accumulation and metabolism are targets in the phage-host arms-race. Our results suggest that like eukaryotic cells, bacteria can differentiate damage-associated and pathogen-associated signals to make threat assessments of cellular injury. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/486733v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@1f69334org.highwire.dtl.DTLVardef@13a4422org.highwire.dtl.DTLVardef@4f3edeorg.highwire.dtl.DTLVardef@a86c43_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2022

MraZ is a transcriptional inhibitor of cell division in Bacillus subtilis

The bacterial division and cell wall (dcw) cluster is a highly conserved region of the genome which encodes several essential cell division factors including the central divisome protein FtsZ. Understanding the regulation of this region is key to our overall understanding of the division process. mraZ is found at the 5 end of the dcw cluster and previous studies have described MraZ as a sequence-specific DNA binding protein. In this article, we investigate MraZ to elucidate its role in Bacillus subtilis. Through our investigation, we demonstrate that increased levels of MraZ result in lethal filamentation due to repression of its own operon (mraZ-mraW-ftsL-pbpB). We observe rescue of filamentation upon decoupling ftsL expression, but not other genes in the operon, from MraZ control. Furthermore, through timelapse microscopy we were able to identify that overexpression of mraZ, results in de-condensation of the FtsZ ring (Z-ring). This is likely due to depletion of FtsL, and thus, we believe the precise role of FtsL is likely in Z-ring maturation and promotion of subsequent treadmilling. Our data suggests that regulation of the mra operon may be an alternative way for cells to quickly arrest cytokinesis potentially during entry into stationary phase and in the event of DNA replication arrest.

microbiology↗

bioRxiv2022

A unique class of Zn2+-binding PBPs underlies cephalosporin resistance and sporogenesis in Clostridioides difficile

{beta}-Lactam antibiotics, particularly cephalosporins, are major risk factors for C. difficile infection (CDI), the most common hospital acquired infection. These broad-spectrum antibiotics irreversibly inhibit penicillin-binding proteins (PBPs), essential enzymes that assemble the bacterial cell wall. Little is known about the C. difficile PBPs, yet they play central roles in the growth, infection, and transmission of this pathogen. In this study we discover that PBP2, essential for vegetative growth, is the primary bactericidal target for {beta}-lactams in C. difficile. We further demonstrate PBP2 is insensitive to cephalosporin inhibition, revealing a key cause of the well-documented, but poorly understood, cephalosporin resistance in C. difficile. For the first time, we determine the crystal structures of C. difficile PBP2, which bears several highly unique features, including significant ligand-induced conformational changes and an active site Zn2+-binding motif that influences {beta}-lactam binding and protein stability. Remarkably, this motif is shared in two other C. difficile PBPs essential for sporulation, PBP3 and SpoVD. While these PBPs are present in a wide range of bacterial taxa, including species in extreme environments and the human gut, they are mostly found in anaerobes, typically Firmicutes. The widespread presence of this convergently evolved thiol-containing motif and its cognate Zn2+ suggests it may function as a redox-sensor to regulate cell wall synthesis for survival in adverse environments. Collectively, our findings address important etiological questions surrounding C. difficile, characterize new elements of PBP structure and function, and lay the groundwork for antibiotic development targeting both C. difficile growth and sporulation.

microbiology↗

bioRxiv2021

GpsB coordinates cell division and cell surface decoration by wall teichoic acids in Staphylococcus aureus

Bacterial cell division is a complex and highly regulated process requiring the coordination of many different proteins. Despite substantial work in model organisms, our understanding of the systems regulating cell division in non-canonical organisms, including critical human pathogens, is far from complete. One such organism is Staphylococcus aureus, a spherical bacterium that lacks known cell division regulatory proteins. Recent studies on GpsB, a protein conserved within the Firmicutes phylum, have provided insight into cell division regulation in S. aureus and other related organisms. It has been revealed that GpsB coordinates cell division and cell wall synthesis in multiple species by interacting with Penicillin Binding Proteins (PBPs) and other partners. In S. aureus, we have previously shown that GpsB directly regulates FtsZ polymerization. In this study, using Bacillus subtilis as a tool, we isolated intragenic and extragenic spontaneous suppressor mutants that abrogate the lethality of S. aureus GpsB overproduction in B. subtilis. Through characterization of these mutants, we identified several key residues important for the function of GpsB. Furthermore, we discovered an additional role for GpsB in wall teichoic acid (WTA) biosynthesis in S. aureus. Specifically, we show that GpsB directly interacts with the wall teichoic acid export protein TarG using a bacterial two-hybrid analysis. We also identified a three-residue motif in GpsB that is crucial for this interaction. Based on the analysis of the localization of TagG in B. subtilis and its homolog TarG in S. aureus, it appears that WTA machinery is a part of the divisome complex. As such, we show additional evidence to the growing body of work that suggests that along with peptidoglycan synthesis, WTA biosynthesis and export may take place at the site of cell division. Taken together, this research illustrates how GpsB performs an essential function in S. aureus by directly linking the tightly regulated cell cycle processes of cell division and WTA-mediated cell surface decoration. IMPORTANCE/AUTHOR SUMMARYCytokinesis in bacteria involves an intricate orchestration of several key cell division proteins and other factors involved in building a robust cell envelope. One of the key factors that differentiates Gram-positive bacteria from Gram-negative bacteria is the presence of teichoic acids interlaced within the Gram-positive cell wall. By characterizing the role of Staphylococcus aureus GpsB, an essential cell division protein in this organism, we have uncovered an additional role for GpsB in wall teichoic acids (WTA) biosynthesis. We show that GpsB directly interacts with TarG of the WTA export complex. We also show this function of GpsB may be conserved in other GpsB homologs as GpsB and the WTA exporter complex follow similar localization patterns. It has been suggested that WTA acts as a molecular signal to control the activity of autolytic enzymes, especially during the separation of conjoined daughter cells. Thus, our results reveal that GpsB, in addition to playing a role in cell division, may also help coordinate WTA biogenesis.

microbiology↗

bioRxiv2021

Phenogenomic characterization of a newly domesticated and novel species from the genus Verrucosispora

The concept of bacterial dark matter stems from our inability to culture most microbes and represents a fundamental hole in our knowledge of microbial diversity. Herein we present the domestication of such an organism: a previously uncultured, novel species from the rare-Actinomycetes genus Verrucosispora. Although initial recovery took >4 months, isolation of phenotypically distinct, domesticated generations occurred within weeks. Two isolates were subjected to phenogenomic analyses, revealing domestication correlated with enhanced growth rates in nutrient-rich media, but diminished capacity to metabolize diverse amino acids. This is seemingly mediated by genomic decay through the pseudogenization of amino acids metabolism genes. Conversely, later generational strains had enhanced spore germination rates, potentially through the reversion of a sporulation-associated kinase from pseudogene to true gene status. We observed that our most wild-type isolate had the greatest potential for antibacterial activity, which correlated with extensive mutational attrition of biosynthetic gene clusters in domesticated strains. Comparative analyses revealed wholesale genomic reordering in strains, with widespread SNP, indel and pseudogene mutations observed. We hypothesize that domestication of this previously unculturable organism resulted from the shedding of genomic flexibility required for life in a dynamic marine environment, parsing out genetic redundancy to allow for a newfound cultivable amenability.

microbiology↗

bioRxiv2021

Assessing the role of cold-shock protein C: A novel regulator of Acinetobacter baumannii biofilm formation and virulence

Acinetobacter baumannii is a formidable opportunistic pathogen that is notoriously difficult to eradicate from hospital settings and can spread quickly via healthcare personnel despite preventive measures. This resilience is often attributed to a proclivity for biofilm formation, which grants A. baumannii a higher tolerance towards external stress, desiccation, and antimicrobials. Despite this, little is known regarding the mechanisms orchestrating A. baumannii biofilm formation. Herein, we performed RNA-seq on biofilm and planktonic populations for the multidrug resistant isolate, AB5075, and identified 438 genes with altered expression. To assess the potential role of genes upregulated within biofilms, we tested the biofilm forming capacity of their respective mutants from an A. baumannii transposon library. In so doing, we uncovered 24 genes whose disruption led to reduced biofilm formation. One such element, cold shock protein C (cspC), produced a mucoidal, non-mucoviscous colony phenotype. RNA-sequencing of this mutant revealed the down regulation of pili and fimbriae in the cspC mutant, which would explain the decreased biofilm observed. Using MIC assays, we note that the mutant displayed increased antibiotic tolerance that we hypothesize is mediated by overexpression of multi-drug efflux pumps and altered mRNA stability of their corresponding transcriptional repressor. Finally, we show that CspC is required for survival during oxidative stress and challenge by the human immune system, and plays a pivotal role during systemic infection. Collectively, our work identifies a cadre of new biofilm associated genes within A. baumannii and provides insight into the global regulatory network of this emerging human pathogen.

microbiology↗

bioRxiv2020

Suppressors of YpsA-mediated cell division inhibition in Bacillus subtilis

Although many bacterial cell division factors have been uncovered over the years, evidence from recent studies points to the existence of yet to be discovered factors involved in cell division regulation. Thus, it is important to identify factors and conditions that regulate cell division to obtain a better understanding of this fundamental biological process. We recently reported that in the Gram-positive organisms Bacillus subtilis and Staphylococcus aureus, increased production of YpsA resulted in cell division inhibition. In this study, we isolated spontaneous suppressor mutations to uncover critical residues of YpsA and the pathways through which YpsA may exert its function. Using this technique, we were able to isolate four unique intragenic suppressor mutations in ypsA (E55D, P79L, R111P, G132E) that rendered the mutated YpsA non-toxic upon overproduction. We also isolated an extragenic suppressor mutation in yfhS, a gene that encodes a protein of unknown function. Subsequent analysis confirmed that cells lacking yfhS were unable to undergo filamentation in response to YpsA overproduction. We also serendipitously discovered that YfhS may play a role in cell size regulation. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=193 SRC="FIGDIR/small/946632v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@1098d63org.highwire.dtl.DTLVardef@216f86org.highwire.dtl.DTLVardef@121050eorg.highwire.dtl.DTLVardef@d2ef3a_HPS_FORMAT_FIGEXP M_FIG C_FIG ABBREVIATED SUMMARYIn Bacillus subtilis, we discovered that increased expression of ypsA results in cell division inhibition and impairment of colony formation on solid medium. Colonies that do arise possess compensatory suppressor mutations. Analysis of one such suppressor mutation led us to a protein of unknown function, YfhS, which appears to play a role in regulating cell length and cell width.

microbiology↗

bioRxiv2018

Discovery of the role of a SLOG superfamily biological conflict systems associated protein IodA (YpsA) in oxidative stress protection and cell division inhibition in Gram-positive bacteria

Bacteria adapt to different environments by regulating cell division and several conditions that modulate cell division have been documented. Understanding how bacteria transduce environmental signals to control cell division is critical to comprehend the global network of cell division regulation. In this article we describe a role for Bacillus subtilis YpsA, an uncharacterized protein of the SLOG superfamily of nucleotide and ligand-binding proteins, in cell division. We observed that YpsA provides protection against oxidative stress as cells lacking ypsA show increased susceptibility to hydrogen peroxide treatment. We found that increased expression of ypsA leads to cell division inhibition due to defective assembly of FtsZ, the tubulin-like essential protein that marks the sites of cell division. We showed that cell division inhibition by YpsA is linked to glucose availability. We generated YpsA mutants that are no longer able to inhibit cell division. Finally, we show that the role of YpsA is possibly conserved in Firmicutes, as overproduction of YpsA in Staphylococcus aureus also impairs cell division. Therefore, we propose ypsA to be renamed as iodA for inhibitor of division.\n\nIMPORTANCEAlthough key players of cell division in bacteria have been largely characterized, the factors that regulate these division proteins are still being discovered and evidence for the presence of yet-to-be discovered factors has been accumulating. How bacteria sense the availability of nutrients and how that information is used to regulate cell division positively or negatively is less well-understood even though some examples exist in the literature. We discovered that a protein of hitherto unknown function belonging to the SLOG superfamily of nucleotide/ligand-binding proteins, YpsA, influences cell division in Bacillus subtilis by integrating metabolic status such as the availability of glucose. We showed that YpsA is important for oxidative stress response in B. subtilis. Furthermore, we provide evidence that cell division inhibition function of YpsA is also conserved in another Firmicute Staphylococcus aureus. This first report on the role of YpsA (IodA) brings us a step closer in understanding the complete tool set that bacteria have at their disposal to regulate cell division precisely to adapt to varying environmental conditions.

microbiology↗