The carR region encodes a light-inducible promoter, a negative regulator of the promoter and a trans-acting activator that controls the light-inducible Myxococcus xanthus carotenoid biosynthesis regulon. DNA sequence analysis revealed, downstream of the promoter, three translationally coupled genes, carQ, carR and carS. Sequencing of mutations demonstrated that carR encoded the negative regulator and was an integral membrane protein. Mutant construction and sequencing revealed that carS was the trans-acting activator and that carQ was a positive regulator of the promoter. Neither gene encodes proteins with known sequence-specific DNA-binding motifs. The sequence of the light-inducible promoter region, identified by primer extension analysis, showed similarity to the consensus sequence of the Escherichia coli stress response ('heat-shock') promoters.
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http://dx.doi.org/10.1111/j.1365-2958.1993.tb00943.x | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Aix-Marseille Université-CNRS UMR 7283, Institut de Microbiologie de la Méditerranée and Turing Center for Living Systems, Marseille 13009, France.
Despite growing awareness of their importance in soil ecology, the genetic and physiological traits of bacterial predators are still relatively poorly understood. In the course of a predator evolution experiment, we identified a class of genotypes leading to enhanced predation against diverse species. RNA-seq analysis demonstrated that this phenotype is linked to the constitutive activation of a predation-specific program.
View Article and Find Full Text PDFJ Bacteriol
January 2025
Department of Microbiology, University of Wisconsin-La Crosse, La Crosse, Wisconsin, USA.
Unlabelled: has numerous two-component signaling systems (TCSs), many of which regulate the complex social behaviors of this soil bacterium. A subset of TCSs consists of NtrC-like response regulators (RRs) and their cognate histidine sensor kinases (SKs). We have previously demonstrated that a multi-component, phosphorelay TCS named NmpRSTU plays a role in social motility.
View Article and Find Full Text PDFCommun Biol
January 2025
Laboratoire de Chimie Bactérienne (LCB) Institut de Microbiologie, Bioénergies et Biotechnologie (IMM), Aix-Marseille Université-CNRS, UMR 7283, Marseille, France.
Cell movement on surfaces relies on focal adhesion complexes (FAs), which connect cytoskeletal motors to the extracellular matrix to produce traction forces. The soil bacterium Myxococcus xanthus uses a bacterial FA (bFA), for surface movement and predation. The bFA system, known as Agl-Glt, is a complex network of at least 17 proteins spanning the cell envelope.
View Article and Find Full Text PDFMany cellular functions depend on the physical properties of the cell's environment. Many bacteria have different types of surface appendages to enable adhesion and motion on various surfaces. is a social soil bacterium with two distinctly regulated modes of surface motility, termed the social motility mode, driven by type IV pili, and the adventurous motility mode, based on focal adhesion complexes.
View Article and Find Full Text PDFNat Commun
January 2025
Joseph Henry Laboratories of Physics, Princeton University, Princeton, NJ, USA.
Colonies of the social bacterium Myxococcus xanthus go through a morphological transition from a thin colony of cells to three-dimensional droplet-like fruiting bodies as a strategy to survive starvation. The biological pathways that control the decision to form a fruiting body have been studied extensively. However, the mechanical events that trigger the creation of multiple cell layers and give rise to droplet formation remain poorly understood.
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