Molecular Biology and Physiology
Research Article | Molecular Biology and PhysiologyRepetitive Elements Contribute to the Diversity and Evolution of Centromeres in the Fungal Genus VerticilliumThe genus Verticillium contains 10 species of plant-associated fungi, some of which are notorious pathogens. Verticillium species evolved by frequent chromosomal rearrangements that contribute to genome plasticity. Centromeres are instrumental for separation of chromosomes during mitosis and meiosis, and failed centromere functionality can lead to chromosomal anomalies. Here, we used a combination of experimental...
Research Article | Molecular Biology and PhysiologySigma 54-Regulated Transcription Is Associated with Membrane Reorganization and Type III Secretion Effectors during Conversion to Infectious Forms of Chlamydia trachomatisThe factors that control the growth and infectious processes for Chlamydia are still poorly understood. This study used recently developed genetic tools to determine the regulon for one of the key transcription factors encoded by Chlamydia, sigma 54. Surrogate and computational analyses provide additional support for the hypothesis that sigma 54 plays a key role in controlling the expression of many components critical...
Research Article | Molecular Biology and PhysiologyStructural Characterization of the Essential Cell Division Protein FtsE and Its Interaction with FtsX in Streptococcus pneumoniaeBacterial cell division is a central process that requires exquisite orchestration of both the cell wall biosynthetic and lytic machineries. The essential membrane complex FtsEX, widely conserved across bacteria, plays a central role by recruiting proteins to the divisome apparatus and by regulating periplasmic muralytic activity from the cytosol. FtsEX is a member of the type VII family of the ABC-superfamily, but instead of being a...
Editor's Pick Research Article | Molecular Biology and PhysiologyInterspecies Microbial Fusion and Large-Scale Exchange of Cytoplasmic Proteins and RNA in a Syntrophic Clostridium CocultureWe report that two different bacterial organisms engage in heterologous cell fusion that leads to massive exchange of cellular material, including proteins and RNA, and the formation of persistent hybrid cells. The interspecies cell fusion observed here involves a syntrophic microbial system, but these heterologous cell fusions were observed even under nonstrict syntrophic conditions, leaving open the possibility that strict syntrophy...
Editor's Pick Research Article | Molecular Biology and PhysiologyThe Nucleoid Occlusion Protein SlmA Binds to Lipid MembranesSuccessful bacterial proliferation relies on the spatial and temporal precision of cytokinesis and its regulation by systems that protect the integrity of the nucleoid. In Escherichia coli, one of these protectors is SlmA protein, which binds to specific DNA sites around the nucleoid and helps to shield the nucleoid from inappropriate bisection by the cell division...
Research Article | Molecular Biology and PhysiologyType IX Secretion System Cargo Proteins Are Glycosylated at the C Terminus with a Novel Linking Sugar of the Wbp/Vim PathwayPorphyromonas gingivalis and Tannerella forsythia, two pathogens associated with severe gum disease, use the type IX secretion system (T9SS) to secrete and attach toxic arrays of virulence factor proteins to their cell surfaces. The proteins are tethered to the outer membrane via glycolipid anchors...
Research Article | Molecular Biology and PhysiologyMolecular Deceleration Regulates Toxicant Release to Prevent Cell Damage in Pseudomonas putida S16 (DSM 28022)Flavin-dependent amine oxidases have received extensive attention because of their importance in drug metabolism, Parkinson’s disease, and neurotransmitter catabolism. However, the underlying molecular mechanisms remain relatively poorly understood. Here, combining the crystal structure of NicA2 (an enzyme in the first step of the bacterial nicotine degradation pathway in ...
Research Article | Molecular Biology and PhysiologyThe ClpX and ClpP2 Orthologs of Chlamydia trachomatis Perform Discrete and Essential Functions in Organism Growth and DevelopmentChlamydia trachomatis is the leading cause of infectious blindness globally and the most reported bacterial sexually transmitted infection both domestically and internationally. Given the economic burden, the lack of an approved vaccine, and the use of broad-spectrum antibiotics for treatment of infections, an understanding of chlamydial growth and development is...
Minireview | Molecular Biology and PhysiologyHistone Modifications and Other Facets of Epigenetic Regulation in Trypanosomatids: Leaving Their MarkHistone posttranslational modifications (PTMs) modulate several eukaryotic cellular processes, including transcription, replication, and repair. Vast arrays of modifications have been identified in conventional eukaryotes over the last 20 to 25 years. While initial studies uncovered these primarily on histone tails, multiple modifications were subsequently found on the central globular domains as well. Histones are evolutionarily...
Editor's Pick Research Article | Molecular Biology and Physiology(p)ppGpp and c-di-AMP Homeostasis Is Controlled by CbpB in Listeria monocytogenesBacteria must efficiently maintain homeostasis of essential molecules to survive in the environment. We found that the levels of c-di-AMP and (p)ppGpp, two nucleotide second messengers that are highly conserved throughout the microbial world, coexist in a homeostatic loop in the facultative intracellular pathogen Listeria monocytogenes. Here, we found that cyclic di-...