Metals in Motion: Understanding Labile Metal Pools in Bacteria.

Metal ions are essential for all life. In microbial cells, potassium (K) is the most abundant cation and plays a key role in maintaining osmotic balance. Magnesium (Mg) is the dominant divalent cation and is required for nucleic acid structure and as an enzyme cofactor.

Structural basis for transcription activation through cooperative recruitment of MntR.

The manganese transport regulator (MntR) from is a dual regulatory protein that responds to heightened Mn availability in the cell by both repressing the expression of uptake transporters and activating the expression of efflux proteins. Recent work indicates that, in its role as an activator, MntR binds several sites upstream of the genes encoding Mn exporters, leading to a cooperative response to manganese. Here, we use cryo-EM to explore the molecular basis of gene activation by MntR and report a structure of four MntR dimers bound to four 18-base pair sites across an 84-base pair regulatory region of the promoter.

Structural basis for transcription activation through cooperative recruitment of MntR.

The manganese transport regulator (MntR) from is a dual regulatory protein that responds to heightened Mn availability in the cell by both repressing the expression of uptake transporters and activating the expression of efflux proteins. Recent work indicates that, in its role as an activator, MntR binds several sites upstream of the genes encoding Mn exporters, leading to a cooperative response to manganese. Here, we use cryo-EM to explore the molecular basis of gene activation by MntR and report a structure of four MntR dimers bound to four 18-base pair sites across an 84-base pair regulatory region of the promoter.

Metalation of Extracytoplasmic Proteins and Bacterial Cell Envelope Homeostasis.

Cell physiology requires innumerable metalloenzymes supported by the selective import of metal ions. Within the crowded cytosol, most enzymes acquire their cognate cofactors from a buffered labile pool. Metalation of membrane-bound and secreted exoenzymes is more problematic since metal concentrations are highly variable outside the cell.