Mycobacterial biotin synthases require an auxiliary protein to convert dethiobiotin into biotin.

Lipid biosynthesis in the pathogen Mycobacterium tuberculosis depends on biotin for posttranslational modification of key enzymes. However, the mycobacterial biotin synthetic pathway is not fully understood. Here, we show that rv1590, a gene of previously unknown function, is required by M.

Commensal antimicrobial resistance mediates microbiome resilience to antibiotic disruption.

Despite their therapeutic benefits, antibiotics exert collateral damage on the microbiome and promote antimicrobial resistance. However, the mechanisms governing microbiome recovery from antibiotics are poorly understood. Treatment of , the world's most common infection, represents the longest antimicrobial exposure in humans.

Lysyl-tRNA synthetase, a target for urgently needed M. tuberculosis drugs.

Tuberculosis is a major global cause of both mortality and financial burden mainly in low and middle-income countries. Given the significant and ongoing rise of drug-resistant strains of Mycobacterium tuberculosis within the clinical setting, there is an urgent need for the development of new, safe and effective treatments. Here the development of a drug-like series based on a fused dihydropyrrolidino-pyrimidine scaffold is described.

Division of labor between SOS and PafBC in mycobacterial DNA repair and mutagenesis.

DNA repair systems allow microbes to survive in diverse environments that compromise chromosomal integrity. Pathogens such as Mycobacterium tuberculosis must contend with the genotoxic host environment, which generates the mutations that underlie antibiotic resistance. Mycobacteria encode the widely distributed SOS pathway, governed by the LexA repressor, but also encode PafBC, a positive regulator of the transcriptional DNA damage response (DDR).

Integrated sensing of host stresses by inhibition of a cytoplasmic two-component system controls acute lung infection.

Bacterial pathogens that infect phagocytic cells must deploy mechanisms that sense and neutralize host microbicidal effectors. For , the causative agent of tuberculosis, these mechanisms allow the bacterium to rapidly adapt from aerosol transmission to initial growth in the lung alveolar macrophage. Here, we identify a branched signaling circuit in that controls growth in the lung through integrated direct sensing of copper ions and nitric oxide by coupled activity of the Rip1 intramembrane protease and the PdtaS/R two-component system.

Two-Way Regulation of MmpL3 Expression Identifies and Validates Inhibitors of MmpL3 Function in .

MmpL3, an essential mycolate transporter in the inner membrane of (), has been identified as a target of multiple, chemically diverse antitubercular drugs. However, several of these molecules seem to have secondary targets and inhibit bacterial growth by more than one mechanism. Here, we describe a cell-based assay that utilizes two-way regulation of MmpL3 expression to readily identify MmpL3-specific inhibitors.

Urinary biomarkers of mycobacterial load and treatment response in pulmonary tuberculosis.

BACKGROUNDControl of the tuberculosis (TB) pandemic remains hindered in part by a lack of simple and accurate measures of treatment efficacy, as current gold standard markers rely on sputum-based assays that are slow and challenging to implement. However, previous work identified urinary N1, N12-diacetylspermine (DiAcSpm), neopterin, hydroxykynurenine, N-acetylhexosamine, ureidopropionic acid, sialic acid, and mass-to-charge ratio (m/z) 241.0903 as potential biomarkers of active pulmonary TB (ATB).

Investigation of ( S)-(-)-Acidomycin: A Selective Antimycobacterial Natural Product That Inhibits Biotin Synthase.

The synthesis, absolute stereochemical configuration, complete biological characterization, mechanism of action and resistance, and pharmacokinetic properties of ( S)-(-)-acidomycin are described. Acidomycin possesses promising antitubercular activity against a series of contemporary drug susceptible and drug-resistant M. tuberculosis strains (minimum inhibitory concentrations (MICs) = 0.

Mass Spectrometric Identification of Urinary Biomarkers of Pulmonary Tuberculosis.

Background: Tuberculosis (TB) is the leading infectious cause of death worldwide. A major barrier to control of the pandemic is a lack of clinical biomarkers with the ability to distinguish active TB from healthy and sick controls and potential for development into point-of-care diagnostics.

Methods: We conducted a prospective case control study to identify candidate urine-based diagnostic biomarkers of active pulmonary TB (discovery cohort) and obtained a separate blinded "validation" cohort of confirmed cases of active pulmonary TB and controls with non-tuberculous pulmonary disease for validation.

Antibiotic treatment for Tuberculosis induces a profound dysbiosis of the microbiome that persists long after therapy is completed.

Mycobacterium tuberculosis, the cause of Tuberculosis (TB), infects one third of the world's population and causes substantial mortality worldwide. In its shortest format, treatment of TB requires six months of multidrug therapy with a mixture of broad spectrum and mycobacterial specific antibiotics, and treatment of multidrug resistant TB is longer. The widespread use of this regimen makes this one of the largest exposures of humans to antimicrobials, yet the effects of TB treatment on intestinal microbiome composition and long-term stability are unknown.

Structure and function of the mycobacterial transcription initiation complex with the essential regulator RbpA.

RbpA and CarD are essential transcription regulators in mycobacteria. Mechanistic analyses of promoter open complex (RPo) formation establish that RbpA and CarD cooperatively stimulate formation of an intermediate (RP2) leading to RPo; formation of RP2 is likely a bottleneck step at the majority of mycobacterial promoters. Once RPo forms, CarD also disfavors its isomerization back to RP2.

The effects of molecular noise and size control on variability in the budding yeast cell cycle.

Molecular noise in gene expression can generate substantial variability in protein concentration. However, its effect on the precision of a natural eukaryotic circuit such as the control of cell cycle remains unclear. We use single-cell imaging of fluorescently labelled budding yeast to measure times from division to budding (G1) and from budding to the next division.

Phosphorylation of the Sic1 inhibitor of B-type cyclins in Saccharomyces cerevisiae is not essential but contributes to cell cycle robustness.

In budding yeast, B-type cyclin (Clb)-dependent kinase activity is essential for S phase and mitosis. In newborn G(1) cells, Clb kinase accumulation is blocked, in part because of the Sic1 stoichiometric inhibitor. Previous results strongly suggested that G(1) cyclin-dependent Sic1 phosphorylation, and its consequent degradation, is essential for S phase.

Ribosome biogenesis is sensed at the Start cell cycle checkpoint.

In the yeast Saccharomyces cerevisiae it has long been thought that cells must reach a critical cell size, called the "setpoint," in order to allow the Start cell cycle transition. Recent evidence suggests that this setpoint is lowered when ribosome biogenesis is slowed. Here we present evidence that yeast can sense ribosome biogenesis independently of mature ribosome levels and protein synthetic capacity.

Coherence and timing of cell cycle start examined at single-cell resolution.

Cell cycle "Start" in budding yeast involves induction of a large battery of G1/S-regulated genes, coordinated with bud morphogenesis. It is unknown how intra-Start coherence of these events and inter-Start timing regularity are achieved. We developed quantitative time-lapse fluorescence microscopy on a multicell-cycle timescale, for following expression of unstable GFP under control of the G1 cyclin CLN2 promoter.

High functional overlap between MluI cell-cycle box binding factor and Swi4/6 cell-cycle box binding factor in the G1/S transcriptional program in Saccharomyces cerevisiae.

In budding yeast, many genes are induced early in the cell cycle. Induction of these genes has been predominantly attributed to two transcription factors, Swi4-Swi6 (SBF) and Mbp1-Swi6 (MBF). Swi4 and Mbp1 are related DNA-binding proteins with dissimilar target sequences.