Molecular Biology and Physiology
- Research Article | Molecular Biology and PhysiologyThe Mitochondrial Calcium Uniporter Interacts with Subunit c of the ATP Synthase of Trypanosomes and Humans
The mitochondrial calcium uniporter (MCU) is essential for the regulation of oxidative phosphorylation in mammalian cells, and we have shown that in Trypanosoma brucei, the etiologic agent of sleeping sickness, this channel is essential for its survival and infectivity. Here we reveal that that Trypanosoma...
- Research Article | Molecular Biology and PhysiologyStructural Basis of Ca2+-Dependent Self-Processing Activity of Repeat-in-Toxin Proteins
The Ca2+-dependent clip-and-link activity of large repeat-in-toxin (RTX) proteins is an exceptional posttranslational process in which an internal domain called a self-processing module (SPM) mediates Ca2+-dependent processing of a highly specific aspartate-proline (Asp-Pro) peptide bond and covalent linkage of the released aspartyl to an adjacent lysine residue through an isopeptide bond. Here, we report the...
- Editor's Pick Research Article | Molecular Biology and PhysiologyThe Absence of (p)ppGpp Renders Initiation of Escherichia coli Chromosomal DNA Synthesis Independent of Growth Rates
Bacterial cells regulate their own chromosomal DNA synthesis and cell division depending on the growth conditions, producing more DNA when growing in nutritionally rich media than in poor media (i.e., human gut versus water reservoir). The accumulation of the nucleotide analog (p)ppGpp is usually viewed as serving to warn cells of impending peril due to otherwise lethal sources of stress, which stops growth and inhibits DNA, RNA, and...
- Research Article | Molecular Biology and PhysiologyPyocin S5 Import into Pseudomonas aeruginosa Reveals a Generic Mode of Bacteriocin Transport
Bacteriocins are toxic polypeptides made by bacteria to kill their competitors, making them interesting as potential antibiotics. Here, we reveal unsuspected commonalities in bacteriocin uptake pathways, through molecular and cellular dissection of the import pathway for the pore-forming bacteriocin pyocin S5 (PyoS5), which targets Pseudomonas aeruginosa. In addition...
- Research Article | Molecular Biology and PhysiologyCyclic di-GMP Signaling in Bacillus subtilis Is Governed by Direct Interactions of Diguanylate Cyclases and Cognate Receptors
Second messengers are free to diffuse through the cells and to activate all responsive elements. Cyclic di-GMP (c-di-GMP) signaling plays an important role in the determination of the life style transition between motility and sessility/biofilm formation but involves numerous distinct synthetases (diguanylate cyclases [DGCs]) or receptor pathways that appear to act in an independent manner. Using...
- Research Article | Molecular Biology and PhysiologySpecies-Specific Recognition of Sulfolobales Mediated by UV-Inducible Pili and S-Layer Glycosylation Patterns
Type IV pili can be found on the cell surface of many archaea and bacteria where they play important roles in different processes. The UV-inducible pili system of Sulfolobales (Ups) pili from the crenarchaeal Sulfolobales species are essential in establishing species-specific mating partners, thereby assisting in genome stability. With this work, we show that different Sulfolobus species have specific regions...
- Letter to the Editor | Molecular Biology and PhysiologyConcerns about Continuing Claims that a Protein Complex Interacts with the Phosphorelay
- Author Reply | Molecular Biology and PhysiologyReply to Losick, “Concerns about Continuing Claims that a Protein Complex Interacts with the Phosphorelay”
- Research Article | Molecular Biology and PhysiologyGenetic and Chemical-Genetic Interactions Map Biogenesis and Permeability Determinants of the Outer Membrane of Escherichia coli
Gram-negative bacteria are a major concern for public health, particularly due to the rise of antibiotic resistance. It is important to understand the biology and permeability of the outer membrane of these bacteria in order to increase the efficacy of antibiotics that have difficulty penetrating this structure. Here, we studied the genetic interactions of a subset of outer membrane-related gene deletions in the model Gram-negative...
- Editor's Pick Research Article | Molecular Biology and PhysiologyIn Vivo Assay Reveals Microbial OleA Thiolases Initiating Hydrocarbon and β-Lactone Biosynthesis
Microbially produced β-lactones are found in antibiotic, antitumor, and antiobesity drugs. Long-chain olefinic membrane hydrocarbons have potential utility as fuels and specialty chemicals. The metabolic pathway to both end products share bacterial enzymes denoted as OleA, OleC, and OleD that transform acyl-CoA cellular intermediates into β-lactones. Bacteria producing membrane hydrocarbons via the Ole pathway additionally express a β-...