Type 1 fimbriae-mediated collective protection against type 6 secretion system attacks.

Bacterial competition may rely on secretion systems such as the type 6 secretion system (T6SS), which punctures and releases toxic molecules into neighboring cells. To subsist, bacterial targets must counteract the threats posed by T6SS-positive competitors. In this study, we used a comprehensive genome-wide high-throughput screening approach to investigate the dynamics of interbacterial competition. Our primary goal was to identify deletion mutants within the well-characterized E. coli K-12 single-gene deletion library, the Keio collection, that demonstrated resistance to T6SS-mediated killing by the enteropathogenic bacterium Cronobacter malonaticus. We identified 49 potential mutants conferring resistance to T6SS and focused our interest on a deletion mutant (∆fimE) exhibiting enhanced expression of type 1 fimbriae. We demonstrated that the presence of type 1 fimbriae leads to the formation of microcolonies and thus protects against T6SS-mediated assaults. Collectively, our study demonstrated that adhesive structures such as type 1 fimbriae confer collective protective behavior against T6SS attacks.IMPORTANCEType 6 secretion systems (T6SS) are molecular weapons employed by gram-negative bacteria to eliminate neighboring microbes. T6SS plays a pivotal role as a virulence factor, enabling pathogenic gram-negative bacteria to compete with the established communities to colonize hosts and induce infections. Gaining a deeper understanding of bacterial interactions will allow the development of strategies to control the action of systems such as the T6SS that can manipulate bacterial communities. In this context, we demonstrate that bacteria targeted by T6SS attacks from the enteric pathogen Cronobacter malonaticus, which poses a significant threat to infants, can develop a collective protective mechanism centered on the production of type I fimbriae. These adhesive structures promote the aggregation of bacterial preys and the formation of microcolonies, which protect the cells from T6SS attacks.

The morphogenic protein CopD controls the spatio-temporal dynamics of PBP1a and PBP2b in Streptococcus pneumoniae.

IMPORTANCE: Penicillin-binding proteins (PBPs) are essential for proper bacterial cell division and morphogenesis. The genome of Streptococcus pneumoniae encodes for two class B PBPs (PBP2x and 2b), which are required for the assembly of the peptidoglycan framework and three class A PBPs (PBP1a, 1b and 2a), which remodel the peptidoglycan mesh during cell division. Therefore, their activities should be finely regulated in space and time to generate the pneumococcal ovoid cell shape. To date, two proteins, CozE and MacP, are known to regulate the function of PBP1a and PBP2a, respectively. In this study, we describe a novel regulator (CopD) that acts on both PBP1a and PBP2b. These findings provide valuable information for understanding bacterial cell division. Furthermore, knowing that ß-lactam antibiotic resistance often arises from PBP mutations, the characterization of such a regulator represents a promising opportunity to develop new strategies to resensitize resistant strains.

Pseudomonas fluorescens MFE01 delivers a putative type VI secretion amidase that confers biocontrol against the soft-rot pathogen Pectobacterium atrosepticum.

The type VI secretion system (T6SS) is a contractile nanomachine widespread in Gram-negative bacteria. The T6SS injects effectors into target cells including eukaryotic hosts and competitor microbial cells and thus participates in pathogenesis and intermicrobial competition. Pseudomonas fluorescens MFE01 possesses a single T6SS gene cluster that confers biocontrol properties by protecting potato tubers against the phytopathogen Pectobacterium atrosepticum (Pca). Here, we demonstrate that a functional T6SS is essential to protect potato tuber by reducing the pectobacteria population. Fluorescence microscopy experiments showed that MFE01 displays an aggressive behaviour with an offensive T6SS characterized by continuous and intense T6SS firing activity. Interestingly, we observed that T6SS firing is correlated with rounding of Pectobacterium cells, suggesting delivery of a potent cell wall targeting effector. Mutagenesis coupled with functional assays then revealed that a putative T6SS secreted amidase, Tae3Pf , is mainly responsible for MFE01 toxicity towards Pca. Further studies finally demonstrated that Tae3Pf is toxic when produced in the periplasm, and that its toxicity is counteracted by the Tai3Pf inner membrane immunity protein.

The Antibacterial Type VII Secretion System of Bacillus subtilis: Structure and Interactions of the Pseudokinase YukC/EssB.

Type VIIb secretion systems (T7SSb) were recently proposed to mediate different aspects of Firmicutes physiology, including bacterial pathogenicity and competition. However, their architecture and mechanism of action remain largely obscure. Here, we present a detailed analysis of the T7SSb-mediated bacterial competition in Bacillus subtilis, using the effector YxiD as a model for the LXG secreted toxins. By systematically investigating protein-protein interactions, we reveal that the membrane subunit YukC contacts all T7SSb components, including the WXG100 substrate YukE and the LXG effector YxiD. YukC's crystal structure shows unique features, suggesting an intrinsic flexibility that is required for T7SSb antibacterial activity. Overall, our results shed light on the role and molecular organization of the T7SSb and demonstrate the potential of B. subtilis as a model system for extensive structure-function studies of these secretion machineries. IMPORTANCE Type VII secretion systems mediate protein extrusion from Gram-positive bacteria and are classified as T7SSa and T7SSb in Actinobacteria and in Firmicutes, respectively. Despite the genetic divergence of T7SSa and T7SSb, the high degree of structural similarity of their WXG100 substrates suggests similar secretion mechanisms. Recent advances revealed the structures of several T7SSa cytoplasmic membrane complexes, but the molecular mechanism of secretion and the T7SSb architecture remain obscure. Here, we provide hints on the organization of T7SSb in B. subtilis and a high-resolution structure of its central pseudokinase subunit, opening new perspectives for the understanding of the T7SSb secretion mechanism by using B. subtilis as an amenable bacterial model.

Membrane fission during bacterial spore development requires cellular inflation driven by DNA translocation.

Bacteria require membrane fission for both cell division and endospore formation. In Bacillus subtilis, sporulation initiates with an asymmetric division that generates a large mother cell and a smaller forespore that contains only a quarter of its genome. As the mother cell membranes engulf the forespore, a DNA translocase pumps the rest of the chromosome into the small forespore compartment, inflating it due to increased turgor. When the engulfing membrane undergoes fission, the forespore is released into the mother cell cytoplasm. The B. subtilis protein FisB catalyzes membrane fission during sporulation, but the molecular basis is unclear. Here, we show that forespore inflation and FisB accumulation are both required for an efficient membrane fission. Forespore inflation leads to higher membrane tension in the engulfment membrane than in the mother cell membrane, causing the membrane to flow through the neck connecting the two membrane compartments. Thus, the mother cell supplies some of the membrane required for the growth of the membranes surrounding the forespore. The oligomerization of FisB at the membrane neck slows the equilibration of membrane tension by impeding the membrane flow. This leads to a further increase in the tension of the engulfment membrane, promoting its fission through lysis. Collectively, our data indicate that DNA translocation has a previously unappreciated second function in energizing the FisB-mediated membrane fission under energy-limited conditions.

A unique bacterial secretion machinery with multiple secretion centers.

The Porphyromonas gingivalis type IX secretion system (T9SS) promotes periodontal disease by secreting gingipains and other virulence factors. By in situ cryoelectron tomography, we report that the P. gingivalis T9SS consists of 18 PorM dimers arranged as a large, caged ring in the periplasm. Near the outer membrane, PorM dimers interact with a PorKN ring complex of ∼52 nm in diameter. PorMKN translocation complexes of a given T9SS adopt distinct conformations energized by the proton motive force, suggestive of different activation states. At the inner membrane, PorM associates with a cytoplasmic complex that exhibits 12-fold symmetry and requires both PorM and PorL for assembly. Activated motors deliver substrates across the outer membrane via one of eight Sov translocons arranged in a ring. The T9SSs are unique among known secretion systems in bacteria and eukaryotes in their assembly as supramolecular machines composed of apparently independently functioning translocation motors and export pores.

Dynamic proton-dependent motors power type IX secretion and gliding motility in Flavobacterium.

Motile bacteria usually rely on external apparatus like flagella for swimming or pili for twitching. By contrast, gliding bacteria do not rely on obvious surface appendages to move on solid surfaces. Flavobacterium johnsoniae and other bacteria in the Bacteroidetes phylum use adhesins whose movement on the cell surface supports motility. In F. johnsoniae, secretion and helicoidal motion of the main adhesin SprB are intimately linked and depend on the type IX secretion system (T9SS). Both processes necessitate the proton motive force (PMF), which is thought to fuel a molecular motor that comprises the GldL and GldM cytoplasmic membrane proteins. Here, we show that F. johnsoniae gliding motility is powered by the pH gradient component of the PMF. We further delineate the interaction network between the GldLM transmembrane helices (TMHs) and show that conserved glutamate residues in GldL TMH2 are essential for gliding motility, although having distinct roles in SprB secretion and motion. We then demonstrate that the PMF and GldL trigger conformational changes in the GldM periplasmic domain. We finally show that multiple GldLM complexes are distributed in the membrane, suggesting that a network of motors may be present to move SprB along a helical path on the cell surface. Altogether, our results provide evidence that GldL and GldM assemble dynamic membrane channels that use the proton gradient to power both T9SS-dependent secretion of SprB and its motion at the cell surface.

Protein Interactome Analysis of the Type IX Secretion System Identifies PorW as the Missing Link between the PorK/N Ring Complex and the Sov Translocon.

The type IX secretion system (T9SS) transports cargo proteins through the outer membrane of Bacteroidetes and attaches them to the cell surface for functions including pathogenesis, gliding motility, and degradation of carbon sources. The T9SS comprises at least 20 different proteins and includes several modules: the trans-envelope core module comprising the PorL/M motor and the PorK/N ring, the outer membrane Sov translocon, and the cell attachment complex. However, the spatial organization of these modules is unknown. We have characterized the protein interactome of the Sov translocon in Porphyromonas gingivalis and identified Sov-PorV-PorA as well as Sov-PorW-PorN-PorK to be novel networks. PorW also interacted with PGN_1783 (PorD), which was required for maximum secretion efficiency. The identification of PorW as the missing link completes a continuous interaction network from the PorL/M motor to the Sov translocon, providing a pathway for cargo delivery and energy transduction from the inner membrane to the secretion pore. IMPORTANCE The T9SS is a newly identified protein secretion system of the Fibrobacteres-Chlorobi-Bacteroidetes superphylum used by pathogens associated with diseases of humans, fish, and poultry for the secretion and cell surface attachment of virulence factors. The T9SS comprises three known modules: (i) the trans-envelope core module comprising the PorL/M motor and the PorK/N ring, (ii) the outer membrane Sov translocon, and (iii) the cell surface attachment complex. The spatial organization and interaction of these modules have been a mystery. Here, we describe the protein interactome of the Sov translocon in the human pathogen Porphyromonas gingivalis and have identified PorW as the missing link which bridges PorN with Sov and so completes a continuous interaction network from the PorL/M motor to the Sov translocon, providing, for the first time, a pathway for cargo delivery and energy transduction from the inner membrane to the secretion pore.

Characterization of TseB: A new actor in cell wall elongation in Bacillus subtilis.

Penicillin-binding proteins (PBPs) are crucial enzymes of peptidoglycan assembly and targets of ß-lactam antibiotics. However, little is known about their regulation. Recently, membrane proteins were shown to regulate the bifunctional transpeptidases/glycosyltransferases aPBPs in some bacteria. However, up to now, regulators of monofunctional transpeptidases bPBPs have yet to be revealed. Here, we propose that TseB could be such a PBP regulator. This membrane protein was previously found to suppress tetracycline sensitivity of a Bacillus subtilis strain deleted for ezrA, a gene encoding a regulator of septation ring formation. In this study, we show that TseB is required for B. subtilis normal cell shape, tseB mutant cells being shorter and wider than wild-type cells. We observed that TseB interacts with PBP2A, a monofunctional transpeptidase. While TseB is not required for PBP2A activity, stability, and localization, we show that the overproduction of PBP2A is deleterious in the absence of TseB. In addition, we showed that TseB is necessary not only for efficient cell wall elongation during exponential phase but also during spore outgrowth, as it was also observed for PBP2A. Altogether, our results suggest that TseB is a new member of the elongasome that regulates PBP2A function during cell elongation and spore germination.

FisB relies on homo-oligomerization and lipid binding to catalyze membrane fission in bacteria.

Little is known about mechanisms of membrane fission in bacteria despite their requirement for cytokinesis. The only known dedicated membrane fission machinery in bacteria, fission protein B (FisB), is expressed during sporulation in Bacillus subtilis and is required to release the developing spore into the mother cell cytoplasm. Here, we characterized the requirements for FisB-mediated membrane fission. FisB forms mobile clusters of approximately 12 molecules that give way to an immobile cluster at the engulfment pole containing approximately 40 proteins at the time of membrane fission. Analysis of FisB mutants revealed that binding to acidic lipids and homo-oligomerization are both critical for targeting FisB to the engulfment pole and membrane fission. Experiments using artificial membranes and filamentous cells suggest that FisB does not have an intrinsic ability to sense or induce membrane curvature but can bridge membranes. Finally, modeling suggests that homo-oligomerization and trans-interactions with membranes are sufficient to explain FisB accumulation at the membrane neck that connects the engulfment membrane to the rest of the mother cell membrane during late stages of engulfment. Together, our results show that FisB is a robust and unusual membrane fission protein that relies on homo-oligomerization, lipid binding, and the unique membrane topology generated during engulfment for localization and membrane scission, but surprisingly, not on lipid microdomains, negative-curvature lipids, or curvature sensing.

Rhomboid intramembrane protease YqgP licenses bacterial membrane protein quality control as adaptor of FtsH AAA protease.

Magnesium homeostasis is essential for life and depends on magnesium transporters, whose activity and ion selectivity need to be tightly controlled. Rhomboid intramembrane proteases pervade the prokaryotic kingdom, but their functions are largely elusive. Using proteomics, we find that Bacillus subtilis rhomboid protease YqgP interacts with the membrane-bound ATP-dependent processive metalloprotease FtsH and cleaves MgtE, the major high-affinity magnesium transporter in B. subtilis. MgtE cleavage by YqgP is potentiated in conditions of low magnesium and high manganese or zinc, thereby protecting B. subtilis from Mn2+ /Zn2+ toxicity. The N-terminal cytosolic domain of YqgP binds Mn2+ and Zn2+ ions and facilitates MgtE cleavage. Independently of its intrinsic protease activity, YqgP acts as a substrate adaptor for FtsH, a function that is necessary for degradation of MgtE. YqgP thus unites protease and pseudoprotease function, hinting at the evolutionary origin of rhomboid pseudoproteases such as Derlins that are intimately involved in eukaryotic ER-associated degradation (ERAD). Conceptually, the YqgP-FtsH system we describe here is analogous to a primordial form of "ERAD" in bacteria and exemplifies an ancestral function of rhomboid-superfamily proteins.

Cell Width Dictates Type VI Secretion Tail Length.

The type VI secretion system (T6SS) is a multiprotein apparatus that injects protein effectors into target cells, hence playing a critical role in pathogenesis and in microbial communities [1-4]. The T6SS belongs to the broad family of contractile injection systems (CISs), such as Myoviridae bacteriophages and R-pyocins, that use a spring-like tail to propel a needle loaded with effectors [5, 6]. The T6SS tail comprises an assembly baseplate on which polymerizes a needle, made of stacked Hcp hexamers, tipped by the VgrG-PAAR spike complex and wrapped by the contractile sheath made of TssB and TssC [7-13]. The T6SS tail is anchored to the cell envelope by a membrane complex that also serves as channel for the passage of the needle upon sheath contraction [14-16]. In most CISs, the length of the tail sheath is invariable and is usually ensured by a dedicated protein called tape measure protein (TMP) [17-22]. Here, we show that the length of the T6SS tail is constant in enteroaggregative Escherichia coli cells, suggesting that it is strictly controlled. By overproducing T6SS tail subunits, we demonstrate that component stoichiometry does not participate to the regulation of tail length. The observation of longer T6SS tails when the apparatus is relocalized at the cell pole further shows that tail length is not controlled by a TMP. Finally, we show that tail stops its elongation when in contact with the opposite membrane and thus that T6SS tail length is determined by the cell width.

Role and Recruitment of the TagL Peptidoglycan-Binding Protein during Type VI Secretion System Biogenesis.

The type VI secretion system (T6SS) is an injection apparatus that uses a springlike mechanism for effector delivery. The contractile tail is composed of a needle tipped by a sharpened spike and wrapped by the sheath that polymerizes in an extended conformation on the assembly platform, or baseplate. Contraction of the sheath propels the needle and effectors associated with it into target cells. The passage of the needle through the cell envelope of the attacker is ensured by a dedicated trans-envelope channel complex. This membrane complex (MC) comprises the TssJ lipoprotein and the TssL and TssM inner membrane proteins. MC assembly is a hierarchized mechanism in which the different subunits are recruited in a specific order: TssJ, TssM, and then TssL. Once assembled, the MC serves as a docking station for the baseplate. In enteroaggregative Escherichia coli, the MC is accessorized by TagL, a peptidoglycan-binding (PGB) inner membrane-anchored protein. Here, we show that the PGB domain is the only functional domain of TagL and that the N-terminal transmembrane region mediates contact with the TssL transmembrane helix. Finally, we conduct fluorescence microscopy experiments to position TagL in the T6SS biogenesis pathway, demonstrating that TagL is recruited to the membrane complex downstream of TssL and is not required for baseplate docking.IMPORTANCE Bacteria use weapons to deliver effectors into target cells. One of these weapons, called the type VI secretion system (T6SS), could be compared to a nano-spear gun using a springlike mechanism for effector injection. By targeting bacteria and eukaryotic cells, the T6SS reshapes bacterial communities and hijacks host cell defenses. In enteroaggregative Escherichia coli, the T6SS is a multiprotein machine that comprises a cytoplasmic tail and a peptidoglycan-anchored trans-envelope channel. In this work, we show that TagL comprises an N-terminal domain that mediates contact with the channel and a peptidoglycan-binding domain that binds the cell wall. We then determine at which stage of T6SS biogenesis TagL is recruited and how TagL absence impacts the assembly pathway.

In vivo TssA proximity labelling during type VI secretion biogenesis reveals TagA as a protein that stops and holds the sheath.

The type VI secretion system (T6SS) is a multiprotein weapon used by bacteria to destroy competitor cells. The T6SS contractile sheath wraps an effector-loaded syringe that is injected into the target cell. This tail structure assembles onto the baseplate that is docked to the membrane complex. In enteroaggregative Escherichia coli, TssA plays a central role at each stage of the T6SS assembly pathway by stabilizing the baseplate and coordinating the polymerization of the tail. Here we adapted an assay based on APEX2-dependent biotinylation to identify the proximity partners of TssA in vivo. By using stage-blocking mutations, we define the temporal contacts of TssA during T6SS biogenesis. This proteomic mapping approach also revealed an additional partner of TssA, TagA. We show that TagA is a cytosolic protein tightly associated with the membrane. Analyses of sheath dynamics further demonstrate that TagA captures the distal end of the sheath to stop its polymerization and to maintain it under the extended conformation.

The cell wall hydrolase Pmp23 is important for assembly and stability of the division ring in Streptococcus pneumoniae.

Bacterial division is intimately linked to synthesis and remodeling of the peptidoglycan, a cage-like polymer that surrounds the bacterial cell, providing shape and mechanical resistance. The bacterial division machinery, which is scaffolded by the cytoskeleton protein FtsZ, includes proteins with enzymatic, structural or regulatory functions. These proteins establish a complex network of transient functional and/or physical interactions which preserve cell shape and cell integrity. Cell wall hydrolases required for peptidoglycan remodeling are major contributors to this mechanism. Consistent with this, their deletion or depletion often results in morphological and/or division defects. However, the exact function of most of them remains elusive. In this work, we show that the putative lysozyme activity of the cell wall hydrolase Pmp23 is important for proper morphology and cell division in the opportunistic human pathogen Streptococcus pneumoniae. Our data indicate that active Pmp23 is required for proper localization of the Z-ring and the FtsZ-positioning protein MapZ. In addition, Pmp23 localizes to the division site and interacts directly with the essential peptidoglycan synthase PBP2x. Altogether, our data reveal a new regulatory function for peptidoglycan hydrolases.

Postnatal maturation of mouse medullo-spinal cerebrospinal fluid-contacting neurons.

The central canal along the spinal cord (SC.) and medulla is characterized by the presence of a specific population of neurons that contacts the cerebrospinal fluid (CSF). These medullo-spinal CSF-contacting neurons (CSF-cNs) are identified by the selective expression of the polycystin kidney disease 2-like 1 ionic channel (PKD2L1 or polycystin-L). In adult, they have been shown to express doublecortin (DCX) and Nkx6.1, two markers of juvenile neurons along with the neuron-specific nuclear protein (NeuN) typically expressed in mature neurons. They were therefore suggested to remain in a rather incomplete maturation state. The aim of this study was to assess whether such juvenile state is stable in postnatal animals or whether CSF-cNs may reach maturity at older stages than neurons in the parenchyma. We show, in the cervical SC. and the brainstem that, in relation to age, CSF-cN density declines and that their cell bodies become more distant from the cc, except in its ventral part. Moreover, in adults (from 1month) by comparison with neonatal mice, we show that CSF-cNs have evolved to a more mature state, as indicated by the increase in the percentage of cells positive for NeuN and of its level of expression. In parallel, CSF-cNs exhibit, in adult, lower DCX immunoreactivity and do not express PSA-NCAM and TUC4, two neurogenic markers. Nevertheless, CSF-cNs still share in adult characteristics of juvenile neurons such as the presence of phospho-CREB and DCX while NeuN expression remained low. This phenotype persists in 12-month-old animals. Thus, despite a pursuit of neuronal maturation during the postnatal period, CSF-cNs retain a durable low differentiated state.

Recruitment, assembly, and molecular architecture of the SpoIIIE DNA pump revealed by superresolution microscopy.

ATP-fuelled molecular motors are responsible for rapid and specific transfer of double-stranded DNA during several fundamental processes, such as cell division, sporulation, bacterial conjugation, and viral DNA transport. A dramatic example of intercompartmental DNA transfer occurs during sporulation in Bacillus subtilis, in which two-thirds of a chromosome is transported across a division septum by the SpoIIIE ATPase. Here, we use photo-activated localization microscopy, structured illumination microscopy, and fluorescence fluctuation microscopy to investigate the mechanism of recruitment and assembly of the SpoIIIE pump and the molecular architecture of the DNA translocation complex. We find that SpoIIIE assembles into ∼45 nm complexes that are recruited to nascent sites of septation, and are subsequently escorted by the constriction machinery to the center of sporulation and division septa. SpoIIIE complexes contain 47±20 SpoIIIE molecules, a majority of which are assembled into hexamers. Finally, we show that directional DNA translocation leads to the establishment of a compartment-specific, asymmetric complex that exports DNA. Our data are inconsistent with the notion that SpoIIIE forms paired DNA conducting channels across fused membranes. Rather, our results support a model in which DNA translocation occurs through an aqueous DNA-conducting pore that could be structurally maintained by the divisional machinery, with SpoIIIE acting as a checkpoint preventing membrane fusion until completion of chromosome segregation. Our findings and proposed mechanism, and our unique combination of innovating methodologies, are relevant to the understanding of bacterial cell division, and may illuminate the mechanisms of other complex machineries involved in DNA conjugation and protein transport across membranes.

FisB mediates membrane fission during sporulation in Bacillus subtilis.

How bacteria catalyze membrane fission during growth and differentiation is an outstanding question in prokaryotic cell biology. Here, we describe a protein (FisB, for fission protein B) that mediates membrane fission during the morphological process of spore formation in Bacillus subtilis. Sporulating cells divide asymmetrically, generating a large mother cell and smaller forespore. After division, the mother cell membranes migrate around the forespore in a phagocytic-like process called engulfment. Membrane fission releases the forespore into the mother cell cytoplasm. Cells lacking FisB are severely and specifically impaired in the fission reaction. Moreover, GFP-FisB forms dynamic foci that become immobilized at the site of fission. Purified FisB catalyzes lipid mixing in vitro and is only required in one of the fusing membranes, suggesting that FisB-lipid interactions drive membrane remodeling. Consistent with this idea, the extracytoplasmic domain of FisB binds with remarkable specificity to cardiolipin, a lipid enriched in the engulfing membranes and regions of negative curvature. We propose that membrane topology at the final stage of engulfment and FisB-cardiolipin interactions ensure that the mother cell membranes are severed at the right time and place. The unique properties of FisB set it apart from the known fission machineries in eukaryotes, suggesting that it represents a new class of fission proteins.

Strategies to adapt cellular processes to nutrient availability in bacteria.

Bacteria are able to adapt to nutrient availability in the environment. For example, when nutritional conditions are not favorable, bacterial size can be reduced and duplication time can be significantly extended in comparison to rich growth conditions. These observations suggest that essential cellular processes like cell division, morphogenesis and chromosome dynamics are highly coordinated with central metabolism to ensure the production of fit progeny. The aim of this review is to provide an overview extending from physiological observations done more than fifty years ago to recent discoveries showing strategies to control essential functions in relation with metabolism in the model bacterium Bacillus subtilis.