Biology subjects

Glatter, T.

Publications and source records attributed to Glatter, T..

At least 37 records · Page 2Linked to original sources

bioRxiv2024

Multiple levels of transcriptional regulation control glycolate metabolism in Paracoccus denitrificans

The hydroxyacid glycolate is a highly abundant carbon source in the environment. Glycolate is produced by unicellular photosynthetic organisms and excreted at petagram scales to the environment, where it serves as growth substrate for heterotrophic bacteria. In microbial metabolism, glycolate is first oxidized to glyoxylate by the enzyme glycolate oxidase. The recently described {beta}-hydroxyaspartate cycle (BHAC) subsequently mediates the carbon-neutral assimilation of glyoxylate into central metabolism in ubiquitous Alpha- and Gammaproteobacteria. While the reaction sequence of the BHAC was elucidated in Paracoccus denitrificans, little is known about the regulation of glycolate and glyoxylate assimilation in this relevant alphaproteobacterial model organism. Here, we show that regulation of glycolate metabolism in P. denitrificans is surprisingly complex, involving two regulators, the IclR-type transcription factor BhcR that acts as an activator for the BHAC gene cluster, as well as the GntR-type transcriptional regulator GlcR, a previously unidentified repressor that controls the production of glycolate oxidase. Furthermore, an additional layer of regulation is exerted at the global level, which involves the transcriptional regulator CceR that controls the switch between glycolysis and gluconeogenesis in P. denitrificans. Together, these regulators control glycolate metabolism in P. denitrificans, allowing the organism to assimilate glycolate together with other carbon substrates in a simultaneous fashion, rather than sequentially. Our results show that the metabolic network of Alphaproteobacteria shows a high degree of flexibility to react to the availability of multiple substrates in the environment.

microbiology↗

bioRxiv2024

DEAD-box ATPase Dbp2 mediates mRNA release after 3'-end formation

mRNA biogenesis in the eukaryotic nucleus is a highly complex process. The numerous RNA processing steps are tightly coordinated to ensure that only fully processed transcripts are released from chromatin for export from the nucleus. Here, we present the hypothesis that fission yeast Dbp2, a ribonucleoprotein complex (RNP) remodelling ATPase of the DEAD-box family, is the key enzyme in an RNP assembly checkpoint at the 3-end of genes. We show that Dbp2 interacts with the cleavage and polyadenylation complex (CPAC) and localizes to cleavage bodies, which are enriched for 3-end processing factors and proteins involved in nuclear RNA surveillance. Upon loss of Dbp2, 3-processed, polyadenylated RNAs accumulate on chromatin and in cleavage bodies, and CPAC components are depleted from the soluble pool. Under these conditions, cells display an increased likelihood to skip polyadenylation sites and a delayed transcription termination, suggesting that levels of free CPAC components are insufficient to maintain normal levels of 3-end processing. Our data support a model in which Dbp2 is the active component of an mRNP remodelling checkpoint that licenses RNA export and is coupled to CPAC release.

molecular biology↗

bioRxiv2024

A deterministic, c-di-GMP-dependent genetic program ensures the generation of phenotypically similar, symmetric daughter cells during cytokinesis

Phenotypic heterogeneity in bacteria results from stochastic processes or deterministic genetic programs. These deterministic programs often incorporate the versatile second messenger c-di-GMP, and by deploying c-di-GMP metabolizing enzyme(s) asymmetrically during cell division give rise to daughter cells with different c-di-GMP levels. By contrast, less is known about how phenotypic heterogeneity is kept to a minimum. Here, we identify a deterministic c-di-GMP-dependent genetic program that is hardwired into the cell cycle of Myxococcus xanthus to minimize phenotypic heterogeneity and guarantee the formation of phenotypically similar daughter cells during division. Cells lacking the diguanylate cyclase DmxA have an aberrant motility behaviour. DmxA is recruited to the cell division site and its activity switched on during cytokinesis, resulting in a dramatic but transient increase in the c-di-GMP concentration. During cytokinesis, this c-di-GMP burst ensures the symmetric incorporation and allocation of structural motility proteins and motility regulators at the new cell poles of the two daughters, thereby generating mirror-symmetric, phenotypically similar daughters with correct motility behaviours. These findings suggest a general c-di-GMP-dependent mechanism for minimizing phenotypic heterogeneity, and demonstrate that bacteria by deploying c-di-GMP metabolizing enzymes to distinct subcellular locations ensure the formation of dissimilar or similar daughter cells.

microbiology↗

bioRxiv2024

Identification, structure and function of the methyltransferase involved in the biosynthesis of the dithiolopyrrolone antibiotic xenorhabdin

Xenorhabdins (XRDs) are produced by Xenorhabdus species and are members of the dithiopyrrolone (DTP) class of natural products that have potent antibacterial, antifungal and anticancer activity. The amide moiety of their DTP core can be methylated or not to fine-tune the bioactivity properties. However, the enzyme responsible for the amide N-methylation remained elusive. Here, we identified and characterized the amide methyltransferase XrdM that is encoded nearly 600 kb away from the XRD gene cluster using proteomic analysis, methyltransferase candidate screening, gene deletion, and allied approaches. In addition, crystallographic analysis and site-directed mutagenesis proved that XrdM is completely distinct from the recently reported DTP methyltransferase DtpM, and that both have been tailored in a species-specific manner for DTP biosynthesis in Gram-negative/positive organisms. Our study expands the limited knowledge of post-NRPS amide methylation in DTP biosynthesis and reveals the evolution of two structurally completely different enzymes for the same reaction in different organisms.

microbiology↗

bioRxiv2023

An interdependent Metabolic and Genetic Network shows emergent properties in vitro

A hallmark of all living organisms is their ability for self-regeneration which requires a tight integration of metabolic and genetic networks. Here we constructed a metabolic and genetic linked in vitro network (MGLN) that shows life-like behavior outside of a cellular context and generates its own building blocks from non-living matter. To this end, we integrated the metabolism of the crotonyl-CoA/ethyl-malonyl-CoA/hydroxybutyryl-CoA (CETCH) cycle with cell-free protein synthesis using recombinant elements (PURE). We demonstrate that the MGLN produces the essential amino acid glycine from inorganic carbon (CO2), and incorporates it into target proteins following DNA-encoded instructions. By programming genetically encoded response into metabolic networks our work opens new avenues for the development of advanced biomimetic systems with emergent properties, including decision-making, self-regeneration and evolution.

synthetic biology↗

bioRxiv2023

A conserved cell-pole determinant organizes proper polar flagellum formation

The coordination of cell cycle progression and flagellar synthesis is a complex process in motile bacteria. In {gamma}-proteobacteria, the localization of the flagellum to the cell pole is mediated by the SRP-type GTPase FlhF. However, the mechanism of action of FlhF, and its relationship with the cell pole landmark protein HubP remain unclear. In this study, we discovered a novel protein called FipA that is required for normal FlhF activity and function in polar flagellar synthesis. We demonstrated that membrane-localized FipA interacts with FlhF and is required for normal flagellar synthesis in Vibrio parahaemolyticus, Pseudomonas putida, and Shewanella putrefaciens, and it does so independently of the polar localization mediated by HubP. FipA exhibits a dynamic localization pattern and is present at the designated pole before flagellar synthesis begins, suggesting its role in licensing flagellar formation. This discovery provides insight into a new pathway for regulating flagellum synthesis and coordinating cellular organization in bacteria that rely on polar flagellation and FlhF-dependent localization.

microbiology↗

bioRxiv2023

Purine nucleotide limitation undermines antibiotic action in clinical Escherichia coli

Metabolic variation across pathogenic bacterial strains can impact their susceptibility to antibiotics1-4 and promote evolution of antimicrobial resistance (AMR)5,6. However, little is known about which metabolic pathways contribute to AMR, and the underlying mechanisms. Here, we measured antibiotic resistance of 15,120 Escherichia coli mutants, each with a single amino acid change in one of 346 essential proteins. Most of the mutant strains that showed resistance to either of the two tested antibiotics carried mutations in metabolic genes. Resistance mutations against a {beta}-lactam antibiotic (carbenicillin) were associated with purine nucleotide biosynthesis and limited the supply of ATP. We show that ATP limitation confers both resistance and tolerance against {beta}-lactam antibiotics by upregulating the purine nucleoside transporter PunC. These results are clinically relevant, because an E. coli strain isolated from a clinical specimen had a purine nucleotide limitation, which reduced its susceptibility to antibiotics.

microbiology↗

bioRxiv2023

During heat stress in Myxococcus xanthus, the CdbS PilZ domain protein, along with two PilZ-DnaK chaperones, perturbs chromosome organization and accelerates cell death

C-di-GMP is a bacterial second messenger that regulates diverse processes in response to environmental or cellular cues. The nucleoid-associated protein (NAP) CdbA in Myxococcus xanthus binds c-di-GMP and DNA in a mutually exclusive manner in vitro. CdbA is essential for viability, and CdbA depletion causes defects in chromosome organization, leading to a block in cell division and, ultimately, cell death. Most NAPs are not essential; therefore, to explore the paradoxical cdbA essentiality, we isolated suppressor mutations that restored cell viability without CdbA. Most mutations mapped to cdbS, which encodes a stand-alone c-di-GMP binding PilZ domain protein, and caused loss-of-function of cdbS. Cells lacking CdbA and CdbS or only CdbS were fully viable and had no defects in chromosome organization. CdbA depletion caused post-transcriptional upregulation of CdbS accumulation, and this CdbS over-accumulation was sufficient to disrupt chromosome organization and cause cell death. CdbA depletion also caused increased accumulation of CsdK1 and CsdK2, two unusual PilZ-DnaK chaperones. During CdbA depletion, CsdK1 and CsdK2, in turn, stabilized CdbS, thereby enabling its increased accumulation and toxicity. Moreover, we demonstrate that heat stress, possibly involving an increased cellular c-di-GMP concentration, induces the CdbA/CsdK1/CsdK2/CdbA system, causing a CsdK1- and CsdK2-dependent increase in CdbS accumulation. Thereby this system accelerates heat stress-induced chromosome mis-organization and cell death. Collectively, this work describes a unique system that contributes to regulated cell death in M. xanthus and suggests a link between c-di-GMP signaling and regulated cell death in bacteria. Author summaryThe nucleotide-based second messenger c-di-GMP in bacteria controls numerous processes in response to environmental or cellular cues. Typically, these processes are related to lifestyle transitions between motile and sessile behaviors. However, c-di-GMP also regulates other processes. In Myxococcus xanthus, CdbA is a DNA-binding and nucleoid-associated protein that helps to organize the large chromosome. CdbA binds c-di-GMP and DNA in a mutually exclusive manner. While other nucleoid-associated proteins are not essential, CdbA is essential. Here, we show that the crucial function of CdbA is to maintain the level of the c-di-GMP-binding PilZ-domain protein CdbS appropriately low. The CdbS level is not only increased upon depletion of CdbA but also in response to heat stress. Under both conditions, the increased CdbS level perturbs chromosome organization and ultimately causes cell death. The CdbA/CdbS system represents a unique system that contributes to regulated cell death in M. xanthus and suggests a link between c-di-GMP signaling and regulated cell death.

microbiology↗

bioRxiv2023

Repertoire and abundance of secreted virulence factors shape the pathogenic capacity of Pseudomonas syringae pv. aptata

Pseudomonas syringae pv. aptata is a member of the sugar beet pathobiome and the causative agent of leaf spot disease. Like many pathogenic bacteria, P. syringae relies on the secretion of toxins, which manipulate host-pathogen interactions, to establish and maintain an infection. This study analyzes the secretome of six pathogenic P. syringae pv. aptata strains with different defined virulence capacities in order to identify common and strain-specific features, and correlate the secretome with disease outcome. All strains show a high type III secretion system (T3SS) and type VI secretion system (T6SS) activity under apoplast-like conditions mimicking the infection. Surprisingly, we found that low pathogenic strains show a higher secretion of most T3SS substrates, whereas a distinct subgroup of four effectors was exclusively secreted in medium and high pathogenic strains. Similarly, we detected two T6SS secretion patterns: while one set of proteins was highly secreted in all strains, another subset consisting of known T6SS substrates and previously uncharacterized proteins was exclusively secreted in medium and high virulence strains. Taken together, our data show that P. syringae pathogenicity is correlated with the repertoire and fine-tuning of effector secretion and indicate distinct strategies for establishing virulence of P. syringae pv. aptata in plants.

microbiology↗

bioRxiv2022

Enhanced assembly of bacteriophage T7 produced in cell-free reactions under simulated microgravity

On-demand biomanufacturing has the potential to improve healthcare and self-sufficiency during space missions. Cell-free transcription and translation reactions combined with DNA blueprints can produce promising therapeutics like bacteriophages and virus-like particles. However, how space conditions affect the synthesis and self-assembly of such complex multi-protein structures is unknown. Here, we characterize the cell-free production of infectious bacteriophage T7 virions under simulated microgravity. Rotation in a 2D-clinostat increased the number of infectious particles compared to static controls. Quantitative analyses by mass spectrometry, immuno-dot-blot and real-time PCR showed no significant differences in protein and DNA contents, suggesting enhanced self-assembly of T7 phages in simulated microgravity. While the effects of genuine space conditions on the cell-free synthesis and assembly of bacteriophages remain to be investigated, our findings support the vision of a cell-free synthesis-enabled "astropharmacy".

synthetic biology↗

bioRxiv2022

Engineered synthetic one-carbon fixation exceeds yield of the Calvin Cycle

One-carbon (C1) feedstocks derived from CO2 and renewable electricity, such as formate, are promising substrates for sustainable production of chemicals, food and fuels. Energetically more efficient, engineered C1-fixation pathways were proposed to increase biomass yields above their natural counterparts, but have so far not been shown to achieve this. Here, we replace the native energy-inefficient Calvin-Benson-Bassham (CBB) cycle in Cupriavidus necator by genomic integration of the synthetic reductive glycine pathway for growth on formate. Our final engineered strain reaches a higher biomass yield than the CBB-cycle-utilizing wild type, showing for the first time that efficiencies found in natural metabolism can be exceeded via a synthetic pathway. This yield increase demonstrates the potential of synthetic metabolism and is an important step towards realizing truly sustainable, economically feasible bio-based production.

synthetic biology↗

bioRxiv2022

DipM controls multiple autolysins and mediates two regulatory feedback loops promoting cell constriction in C. crescentus

Proteins containing a catalytically inactive LytM-type endopeptidase domain have emerged as important regulators of cell wall-degrading enzymes in bacteria. Although these so-called LytM factors are wide-spread among species, the range of functions they fulfill and their precise modes of action are still incompletely understood. In this work, we study the LytM factor DipM, a protein required for proper cell division in the model species C. crescentus. We show that the LytM domain of DipM interacts directly with multiple autolysins, including the lytic transglycosylases SdpA and SdpB, the amidase AmiC and the putative carboxypeptidase CrbA, and stimulates the activities of SdpA and AmiC. The crystal structure of the LytM domain of DipM reveals conserved features, including a distinctive groove. Modeling studies suggest that this groove could represent the docking site of AmiC. The architecture of the binding interface in the DipM-AmiC complex is very similar to that observed for the LytM domain of EnvC in complex with its autoinhibitory restraining arm, suggesting a conserved role of the groove in the interaction of LytM factors with their (auto-)regulatory targets. In line with this hypothesis, a mutation in the groove abolishes DipM function. Interestingly, single-molecule tracking studies reveal that the recruitment of DipM and its regulatory targets SdpA and SdpB to the division site is mutually interdependent, with DipM establishing a self-reinforcing cycle that gradually increases lytic transglycosylase activity at the cell center as division progresses. At the same time, the DipM-dependent activation of AmiC leads to the production of denuded peptidoglycan, generating a spatial cue that attracts FtsN to the division site and thus, in turn, again promotes the recruitment of DipM. Collectively, these findings show that DipM is a central regulator that acts at the intersection of different peptidoglycan remodeling pathways and coordinates the activities of various classes of autolysins to promote cell constriction and daughter cell separation.

microbiology↗

bioRxiv2022

Implementation of the β-hydroxyaspartate cycle increases growth performance of Pseudomonas putida on the PET monomer ethylene glycol

Ethylene glycol (EG) is a promising next generation feedstock for bioprocesses. It is a key component of the ubiquitous plastic polyethylene terephthalate (PET) and other polyester fibers and plastics, used in antifreeze formulations, and can also be generated by electrochemical conversion of syngas, which makes EG a key compound in a circular bioeconomy. The majority of biotechnologically relevant bacteria assimilate EG via the glycerate pathway, a wasteful metabolic route that releases CO2 and requires reducing equivalents as well as ATP. In contrast, the recently characterized {beta}-hydroxyaspartate cycle (BHAC) provides a more efficient, carbon-conserving route for C2 assimilation. Here we aimed at overcoming the natural limitations of EG metabolism in the industrially relevant strain Pseudomonas putida KT2440 by replacing the native glycerate pathway with the BHAC. We first prototyped the core reaction sequence of the BHAC in Escherichia coli before establishing the complete four-enzyme BHAC in Pseudomonas putida. Directed evolution on EG resulted in an improved strain that exhibits 35% faster growth and 20% increased biomass yield compared to a recently reported P. putida strain that was evolved to grow on EG via the glycerate pathway. Genome sequencing and proteomics highlight plastic adaptations of the genetic and metabolic networks in response to the introduction of the BHAC into P. putida and identify key mutations for its further integration during evolution. Taken together, our study shows that the BHAC can be utilized as plug-and-play module for the metabolic engineering of two important microbial platform organisms, paving the way for multiple applications for a more efficient and carbon-conserving upcycling of EG in the future.

synthetic biology↗

bioRxiv2022

Structural and functional analysis of the cerato-platanin-like effector protein Cpl1 suggests diverging functions in smut fungi

Plant pathogenic fungi are causative agents of the majority of plant diseases and can lead to severe crop loss in infected populations. Fungal colonization is achieved by combining different strategies, such as avoiding and counteracting the plant immune system and manipulating the host metabolome. Of major importance are effector proteins secreted by the fungi that fulfill diverse functions to support the infection process. Most of these proteins are highly specialized and structural and biochemical information is often absent. Here, we present the atomic structures of the cerato-platanin-like protein Cpl1 from Ustilago maydis and its homolog Uvi2 from Ustilago hordei. Both proteins adopt a double-{Psi}-{beta}-barrel architecture reminiscent of cerato-platanin proteins, a class so far not described in smut fungi. Our structure-function analysis shows that Cpl1 binds to soluble chitin fragments via two extended grooves at the dimer interface of the two monomer molecules. This carbohydrate-binding mode has not been observed previously and expands the repertoire of chitin-binding proteins. Cpl1 localizes to the cell wall of U. maydis and specifically enriches cell-wall degrading and -decorating proteins during maize infection. The architecture of Cpl1 harboring four surface exposed loop regions supports the idea that it might play a role in spatial coordination of these proteins. While deletion of cpl1 has only mild effects on the virulence of U. maydis, a recent study showed that deletion of uvi2 strongly impairs U. hordei virulence. Our structural comparison between Cpl1 and Uvi2 reveals sequence variations in the loop regions which might explain a diverging function.

biochemistry↗

bioRxiv2022

Constitutive production of flagellar proteins is required for proper flagellation in Shewanella putrefaciens

Flagella are multiprotein complexes whose assembly and positioning requires complex spatiotemporal control. Flagellar assembly is thought to be controlled by several transcriptional tiers, which is mediated through various master regulators. Here, we revisited the regulation of flagellar genes in polarly flagellated gammaproteobacteria by the regulators FlrA, RpoN ({sigma}54) and FliA ({sigma}28) in Shewanella putrefaciens CN-32 at the transcript and protein level. As expected, strict control at both levels occurred for for highly abundant flagellar proteins, including the building blocks for the outer rings, rod, hook and filament. In contrast, a number of regulatory and structural proteins were always present also in the absence of the main regulators. Initiation of flagella assembly and motor activation likely relies on the abundance control of only few structural key components required for formation of the MS- and C-ring and the flagellar type III secrection system. We identified {sigma}70-dependent promoters driving constitutive expression of some flagellar genes including the regulators of flagellar number and positioning, FlhF and FlhG. Reduction of the constitutive expression levels resulted in emergence of hyperflagellation. Thus, basal expression and presence of flagellar proteins is required for proper flagellation, which adds a deeper layer to the regulation of flagellar synthesis and assembly. SignificanceThe tier-based transcriptional regulation underlying bacterial flagella synthesis is - with certain variations - well-established in various species. Here we show that initiation and proceeding of flagellar synthesis can be simply based on the control of some key components and highly abundant building blocks. We further identified a 'tier zero, a set of constitutively produced flagellar regulators and building blocks, which is required, for example, to maintain the flagellar counter. We expect this not only to apply to our model species Shewanella, but also to other flagella regulation systems in bacteria.

microbiology↗

bioRxiv2022

Evidence for a widespread third system for bacterial polysaccharide export across the outer membrane comprising a composite OPX/β-barrel translocon

In Gram-negative bacteria, secreted polysaccharides have multiple critical functions. In Wzx/Wzy- and ABC transporter-dependent pathways, an outer membrane (OM) polysaccharide export (OPX) type translocon exports the polysaccharide across the OM. The paradigm OPX protein WzaE. coli is an octamer, in which the eight C-terminal domains form an -helical OM pore, and the eight copies of the three N-terminal domains (D1-D3) a periplasmic cavity. In synthase-dependent pathways, the OM translocon is a 16- to 18- stranded {beta}-barrel protein. In Myxococcus xanthus, the secreted polysaccharide EPS is synthesized in a Wzx/Wzy-dependent pathway. Here, using experiments and computational structural biology, we characterize EpsX as an OM 18-stranded {beta}-barrel protein important for EPS synthesis and identify AlgE, a {beta}-barrel translocon of a synthase-dependent pathway, as its closest structural homolog. We also find that EpsY, the OPX protein of the EPS pathway, only consists of the periplasmic D1 and D2 domains and lacks the domain for spanning the OM (henceforth D1D2OPX protein). In vivo, EpsX and EpsY mutually stabilize each other, supporting their direct interaction. Based on these observations, we propose a model whereby EpsY and EpsX make up a novel type of translocon for polysaccharide export across the OM. Specifically, in this composite translocon, EpsX functions as the OM-spanning translocon together with the periplasmic D1D2OPX protein EpsY. Based on computational genomics, similar composite systems are present widespread in Gram-negative bacteria. This model provides a framework for these proteins future experimental characterization.

microbiology↗

bioRxiv2022

Pilotins are mobile T3SS components involved in assembly and substrate specificity of the bacterial type III secretion system

In animal pathogens, assembly of the type III secretion system injectisome requires the presence of so-called pilotins, small lipoproteins that assist the formation of the secretin ring in the outer membrane. Using a combination of functional assays, interaction studies, proteomics, and live-cell microscopy, we determined the contribution of the pilotin to the assembly, function, and substrate selectivity of the T3SS and identified potential new downstream roles of pilotin proteins. In absence of its pilotin SctG, Yersinia enterocolitica forms few, largely polar injectisome sorting platforms and needles. In line, most export apparatus subcomplexes are mobile in these strains, suggesting the absence of fully assembled injectisomes. Remarkably, while absence of the pilotin all but prevents export of early T3SS substrates, such as the needle subunits, it has little effect on secretion of late T3SS substrates, including the virulence effectors. We found that pilotins transiently interact with other injectisome components such as the secretin in the outer membrane, but mostly form transient mobile clusters in the bacterial membrane, which do not colocalize with assembled injectisomes. Together, these findings provide a new view on the role of pilotins during and after assembly of type III secretion injectisomes.

microbiology↗

bioRxiv2021

A GGDEF domain serves as a spatial on-switch for a phosphodiesterase by direct interaction with a polar landmark protein

In bacteria, the monopolar localization of enzymes and protein complexes can result in a bi-modal distribution of enzyme activity between the dividing cells and heterogeneity of cellular behaviors. In Shewanella putrefaciens, the multidomain hybrid diguanylate cyclase/phosphodiesterase PdeB, which degrades the secondary messenger c-di-GMP, is located at the flagellated cell pole. Here we show how PdeB polar recruitment is mediated by direct interaction between the inactive diguanylate cyclase (GGDEF) domain of PdeB and the C-terminal FimV domain of the polar landmark protein HubP. We demonstrate that this interaction is crucial for full function of PdeB as a phosphodiesterase. Thus, the GGDEF domain serves as a spatially controlled on-switch that effectively restricts PdeBs activity to the flagellated cell pole. We further show that PdeB regulates abundance and activity of at least two crucial surface-interaction factors, the BpfA surface adhesion protein and the MSHA type IV pilus. The heterogeneity in c-di-GMP concentrations that is generated by differences in abundance and temporal polar appearance of PdeB as well as by bi-modal distribution after cell fission orchestrates the population behavior with respect to cell-surface interaction and environmental spreading. SignificancePhenotypic heterogeneity benefits the proliferation of microbial populations in changing environments. Such heterogeneity can be created by recruitment of enzymatic activity to specific cellular compartments, e.g., the cell pole. Here we show how a GGDEF domain of a multidomain phosphodiesterase has adopted the function as a spatial on-switch that is specifically activated upon direct interaction with a polar landmark protein.

microbiology↗