A metal-trap tests and refines blueprints to engineer cellular protein metalation with different elements.

It has been challenging to test how proteins acquire specific metals in cells. The speciation of metalation is thought to depend on the preferences of proteins for different metals competing at intracellular metal-availabilities. This implies mis-metalation may occur if proteins become mis-matched to metal-availabilities in heterologous cells.

High-affinity agonism at the P2X receptor is mediated by three residues outside the orthosteric pocket.

P2X receptors are trimeric ATP-gated ion channels that activate diverse signaling cascades. Due to its role in apoptotic pathways, selective activation of P2X is a potential experimental tool and therapeutic approach in cancer biology. However, mechanisms of high-affinity P2X activation have not been defined.

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.

Calculating metalation in cells reveals CobW acquires Co for vitamin B biosynthesis while related proteins prefer Zn.

Protein metal-occupancy (metalation) in vivo has been elusive. To address this challenge, the available free energies of metals have recently been determined from the responses of metal sensors. Here, we use these free energy values to develop a metalation-calculator which accounts for inter-metal competition and changing metal-availabilities inside cells.