Caulobacter crescentus
Research Article | Molecular Biology and PhysiologyLoss of Bacterial Cell Pole Stabilization in Caulobacter crescentus Sensitizes to Outer Membrane Stress and Peptidoglycan-Directed AntibioticsMaintenance of an intact cell envelope is essential for free-living bacteria to protect themselves against their environment. In the case of rod-shaped bacteria, the poles of the cell are potential weak points in the cell envelope due to the high curvature of the layers and the need to break and reform the cell envelope at the division plane as the cells divide. We have found that TipN, a factor required for correct division and cell...
Research Article | Molecular Biology and PhysiologyNovel Divisome-Associated Protein Spatially Coupling the Z-Ring with the Chromosomal Replication Terminus in Caulobacter crescentusGrowing bacteria require careful tuning of cell division processes with dynamic organization of replicating chromosomes. In enteric bacteria, ZapA associates with the cytoskeletal Z-ring and establishes a physical linkage to the chromosomal replication terminus through its interaction with ZapB-MatP-DNA complexes. However, because ZapB and MatP are found only in enteric bacteria, it remains unclear how the Z-ring and the terminus are...
Research Article | Molecular Biology and PhysiologyFeedback Control of a Two-Component Signaling System by an Fe-S-Binding Receiver DomainTwo-component signal transduction systems (TCSs) are broadly conserved in the bacterial kingdom and generally contain two molecular components, a sensor histidine kinase and a receiver protein. Sensor histidine kinases alter their phosphorylation state in direct response to a physical or chemical cue, whereas receiver proteins “receive” the phosphoryl group from the kinase to regulate a change in cell physiology. We have discovered that...
Research Article | Molecular Biology and PhysiologyA CRISPR Interference System for Efficient and Rapid Gene Knockdown in Caulobacter crescentusCaulobacter crescentus is a major model organism for understanding cell cycle regulation and cellular asymmetry. The current genetic tools for deleting or silencing the expression of individual genes, particularly those essential for viability, are time-consuming and labor-intensive, which limits global genetic studies. Here, we optimized CRISPR interference (CRISPRi...
Research Article | Molecular Biology and PhysiologyMolecular Basis and Ecological Relevance of Caulobacter Cell Filamentation in Freshwater HabitatsMany bacteria drastically change their cell size and morphology in response to changing environmental conditions. Here, we demonstrate that the freshwater bacterium Caulobacter crescentus and related species transform into filamentous cells in response to conditions that commonly occur in their natural habitat as a result of algal blooms during the warm summer months...
Research Article | Molecular Biology and PhysiologyChromosome Dynamics in Bacteria: Triggering Replication at the Opposite Location and Segregation in the Opposite DirectionBacteria can accomplish surprising levels of organization in the absence of membrane organelles by constructing subcellular asymmetric protein gradients. These gradients are composed of regulators that can either trigger or inhibit cell cycle events from distinct cell poles. In Caulobacter crescentus, the onset of chromosome replication and segregation from the...
- Research ArticleLayered Structure and Complex Mechanochemistry Underlie Strength and Versatility in a Bacterial Adhesive
There is an urgent need for strong, biocompatible bioadhesives that perform underwater. To strongly adhere to surfaces and resist flow underwater, the bacterium Caulobacter crescentus produces an adhesive called the holdfast, the mechanochemistry of which remains undefined. We show that the holdfast is a layered structure with a stiff core layer and a polymeric brush layer and consists of polysaccharides, polypeptides, and DNA...
- Research ArticleCohesive Properties of the Caulobacter crescentus Holdfast Adhesin Are Regulated by a Novel c-di-GMP Effector Protein
Exopolysaccharide (EPS) adhesins are important determinants of bacterial surface colonization and biofilm formation. Biofilms are a major cause of chronic infections and are responsible for biofouling on water-exposed surfaces. To tackle these problems, it is essential to dissect the processes leading to surface colonization at the molecular and cellular levels. Here we describe a novel c-di-GMP effector, HfsK, that contributes to the...