LIVE-PAINT allows super-resolution microscopy inside living cells using reversible peptide-protein interactions.

We present LIVE-PAINT, a new approach to super-resolution fluorescent imaging inside live cells. In LIVE-PAINT only a short peptide sequence is fused to the protein being studied, unlike conventional super-resolution methods, which rely on directly fusing the biomolecule of interest to a large fluorescent protein, organic fluorophore, or oligonucleotide. LIVE-PAINT works by observing the blinking of localized fluorescence as this peptide is reversibly bound by a protein that is fused to a fluorescent protein.

The cytochrome bd-I respiratory oxidase augments survival of multidrug-resistant Escherichia coli during infection.

Nitric oxide (NO) is a toxic free radical produced by neutrophils and macrophages in response to infection. Uropathogenic Escherichia coli (UPEC) induces a variety of defence mechanisms in response to NO, including direct NO detoxification (Hmp, NorVW, NrfA), iron-sulphur cluster repair (YtfE), and the expression of the NO-tolerant cytochrome bd-I respiratory oxidase (CydAB). The current study quantifies the relative contribution of these systems to UPEC growth and survival during infection.

CydDC-mediated reductant export in Escherichia coli controls the transcriptional wiring of energy metabolism and combats nitrosative stress.

The glutathione/cysteine exporter CydDC maintains redox balance in Escherichia coli. A cydD mutant strain was used to probe the influence of CydDC upon reduced thiol export, gene expression, metabolic perturbations, intracellular pH homoeostasis and tolerance to nitric oxide (NO). Loss of CydDC was found to decrease extracytoplasmic thiol levels, whereas overexpression diminished the cytoplasmic thiol content.

The CydDC Family of Transporters and Their Roles in Oxidase Assembly and Homeostasis.

The CydDC complex of Escherichia coli is a heterodimeric ATP-binding cassette type transporter (ABC transporter) that exports the thiol-containing redox-active molecules cysteine and glutathione. These reductants are thought to aid redox homeostasis of the periplasm, permitting correct disulphide folding of periplasmic and secreted proteins. Loss of CydDC results in the periplasm becoming more oxidising and abolishes the assembly of functional bd-type respiratory oxidases that couple the oxidation of ubiquinol to the reduction of oxygen to water.