Molecular Biology and Physiology
Research Article | Molecular Biology and PhysiologyRules of Expansion: an Updated Consensus Operator Site for the CopR-CopY Family of Bacterial Copper Exporter System RepressorsMany Gram-positive bacteria respond to copper stress by upregulating a copper export system controlled by a copper-sensitive repressor, CopR-CopY. The previous operator sequence for this family of proteins had been identified as TACANNTGTA. Here, using several recombinant proteins and mutations in various DNA fragments, we define those 10 bases as necessary but not sufficient for binding and in doing so, refine the cop operon...
Research Article | Molecular Biology and PhysiologyPhosphoproteomics of Aspergillus fumigatus Exposed to the Antifungal Drug CaspofunginAspergillus fumigatus is an opportunistic human-pathogenic fungus causing allergic reactions or systemic infections, such as invasive pulmonary aspergillosis in immunocompromised patients. Caspofungin is an echinocandin that impacts the construction of the fungal cell wall by inhibiting the biosynthesis of the β-1,3-glucan polysaccharide. Caspofungin is a fungistatic...
Research Article | Molecular Biology and PhysiologyRocA Regulates Phosphatase Activity of Virulence Sensor CovS of Group A Streptococcus in Growth Phase- and pH-Dependent MannersThe emergence of invasive group A streptococcal infections has been reported worldwide. Clinical isolates that have spontaneous mutations or a truncated allele of the rocA gene (e.g., emm3-type isolates) are considered to be more virulent than isolates with the intact rocA gene (e.g., emm1-type isolates). RocA is a positive regulator of covR and has been shown to enhance the phosphorylation...
Research Article | Molecular Biology and PhysiologyInteractions of PatA with the Divisome during Heterocyst Differentiation in AnabaenaAnabaena is a cyanobacterial model that represents an ancient and simple form of biological multicellularity. The Anabaena organism is a filament of cohesive and communicating cells that can include cells specialized in different tasks. Thus, under conditions of nitrogen scarcity, certain cells of the filament differentiate into heterocysts, which fix atmospheric nitrogen and provide organic nitrogen to the rest of...
Research Article | Molecular Biology and PhysiologyGenomewide Stabilization of mRNA during a “Feast-to-Famine” Growth Transition in Escherichia coliThe ability to rapidly respond to changing nutrients is crucial for E. coli to survive in many environments, including the gut. Reorganization of gene expression is the first step used by bacteria to adjust their metabolism accordingly. It involves fine-tuning of both transcription (transcriptional regulation) and mRNA stability (posttranscriptional regulation). While...
Research Article | Molecular Biology and PhysiologyA Zinc Cluster Transcription Factor Contributes to the Intrinsic Fluconazole Resistance of Candida aurisCandida auris is a recently emerged pathogenic yeast that within a few years after its initial description has spread all over the globe. C. auris is a major concern for human health, because it can cause life-threatening systemic infections, is easily transmissible, and is difficult to eradicate...
Research Article | Molecular Biology and PhysiologyA Mutant RNA Polymerase Activates the General Stress Response, Enabling Escherichia coli Adaptation to Late Prolonged Stationary PhaseAn important general mechanism of a bacterium’s adaptation to its environment involves adjusting the balance between growing fast and tolerating stresses. One paradigm where this plays out is in prolonged stationary phase: early studies showed that attenuation, but not complete elimination, of the general stress response enables early adaptation of the bacterium E. coli...
Research Article | Molecular Biology and PhysiologyFunctional Characterization of Clinical Isolates of the Opportunistic Fungal Pathogen Aspergillus nidulansImmunocompromised patients are susceptible to infections with opportunistic filamentous fungi from the genus Aspergillus. Although A. fumigatus is the main etiological agent of Aspergillus species-related infections, other species, such as A. nidulans, are prevalent in a condition-...
Research Article | Molecular Biology and PhysiologyConvergence between Regulation of Carbon Utilization and Catabolic Repression in Xanthophyllomyces dendrorhousThe conditions affecting catabolic regulation in X. dendrorhous are complex and suggest the presence of an alternative mechanism of regulation. The repressors Mig1, Cyc8, and Tup1 are essential elements for the regulation of the use of glucose and other carbon sources. All play different roles but, depending on the growth conditions, can work in convergent,...
Research Article | Molecular Biology and PhysiologyMolecular Mechanisms of Phosphate Stress Activation of Pseudomonas aeruginosa Quorum Sensing SystemsIt is not fully understood how phosphate deficiency could influence the virulence of Pseudomonas aeruginosa through modulation of the bacterial QS systems. This report presents a systemic investigation on the impact of phosphate depletion on the hierarchy of quorum sensing systems of P. aeruginosa....