Latest Articles
Research Article | Applied and Environmental ScienceBacterial Secondary Metabolite Biosynthetic Potential in Soil Varies with Phylum, Depth, and Vegetation TypeMicrobes produce specialized compounds to compete or communicate with one another and their environment. Some of these compounds, such as antibiotics, are also useful in medicine and biotechnology. Historically, most antibiotics have come from soil bacteria which can be isolated and grown in the lab. Though the vast majority of soil bacteria cannot be isolated, we can extract their genetic information and search it for genes which...
Research Article | Host-Microbe BiologyPrions from Sporadic Creutzfeldt-Jakob Disease Patients Propagate as Strain MixturessCJD occurrence is currently assumed to result from spontaneous and stochastic formation of a misfolded PrP nucleus in the brains of affected patients. This original nucleus then recruits and converts nascent PrPC into PrPSc, leading to the propagation of prions in the patient’s brain. Our study demonstrates the coexistence of two prion strains in the brains of a majority of the 23 sCJD patients investigated. The...
Research Article | Molecular Biology and PhysiologyHfq and sRNA 179 Inhibit Expression of the Pseudomonas aeruginosa cAMP-Vfr and Type III Secretion RegulonsControl of gene expression by small noncoding RNA (sRNA) is well documented but underappreciated. Deep sequencing of mRNA preparations from Pseudomonas aeruginosa suggests that >500 sRNAs are generated. Few of those sRNAs have defined roles in gene expression. To address that knowledge gap, we constructed an sRNA expression library and identified sRNA 179 as a...
Research Article | Molecular Biology and PhysiologyBiophysical Properties of Escherichia coli Cytoplasm in Stationary Phase by Superresolution Fluorescence MicroscopyBacteria in nature usually lack sufficient nutrients to enable growth and replication. Such starved bacteria adapt into a quiescent state known as the stationary phase. The chromosomal DNA is protected against oxidative damage, and ribosomes are stored in a dimeric structure impervious to digestion. Stationary-phase bacteria can recover and grow quickly when better nutrient conditions arise. The biochemistry of stationary-phase...
Research Article | Host-Microbe BiologyInhibition of the Super Elongation Complex Suppresses Herpes Simplex Virus Immediate Early Gene Expression, Lytic Infection, and Reactivation from LatencyHSV infections can cause pathologies ranging from recurrent lesions to significant ocular disease. Initiation of lytic infection and reactivation from latency in sensory neurons are dependent on the induced expression of the viral immediate early genes. Transcription of these genes is controlled at multiple levels, including modulation of the chromatin state of the viral genome and appropriate recruitment of transcription factors and...
Research Article | Host-Microbe BiologyThe Novel J-Domain Protein Mrj1 Is Required for Mitochondrial Respiration and Virulence in Cryptococcus neoformansCryptococcus neoformans is the causative agent of cryptococcal meningitis, a disease responsible for ∼15% of all HIV-related deaths. Unfortunately, development of antifungal drugs is challenging because potential targets are conserved between humans and C. neoformans. In this context, we...
Research Article | Ecological and Evolutionary ScienceEscherichia coli K-12 Lacks a High-Affinity Assimilatory Cysteine ImporterThis investigation discovered that Escherichia coli lacks a transporter dedicated to the assimilation of cysteine, an outcome that is in striking contrast to the many transporters devoted to the other 19 amino acids. We ascribe the lack of a high-affinity cysteine importer to two considerations. First, the chemical reactivity of this amino acid is unique, and its...
Research Article | Molecular Biology and PhysiologyArchaeal Chromatin Proteins Cren7 and Sul7d Compact DNA by Bending and BridgingA long-standing question is how chromosomal DNA is packaged in Crenarchaeota, a major group of archaea, which synthesize large amounts of unique small DNA-binding proteins but in general contain no archaeal histones. In the present work, we tested our hypothesis that the two well-studied crenarchaeal chromatin proteins Cren7 and Sul7d compact DNA by both DNA bending and bridging. We show that the two proteins are capable of compacting...
Research Article | Host-Microbe BiologyIntegrin α5β1, as a Receptor of Fibronectin, Binds the FbaA Protein of Group A Streptococcus To Initiate Autophagy during InfectionAutophagy is generally considered a strategy used by the innate immune system to eliminate invasive pathogens through capturing and transferring them to lysosomes. Currently, researchers pay more attention to how virulence factors secreted by GAS regulate the autophagic process. Here, we provide the first evidence that the structural protein FbaA of M1 GAS strain SF370 is a potent inducer of autophagy in epithelial cells. Furthermore,...
Research Article | Ecological and Evolutionary SciencePan-GWAS of Streptococcus agalactiae Highlights Lineage-Specific Genes Associated with Virulence and Niche AdaptationGBS is a leading cause of mortality in newborn babies in high- and low-income countries worldwide. Different strains of GBS are characterized by different degrees of virulence, where some are harmlessly carried by humans or animals and others are much more likely to cause disease. The genome sequences of almost 2,000 GBS samples isolated from both animals and humans in high- and low- income countries were analyzed using a pan-genome-...