Structural dynamics in the evolution of a bilobed protein scaffold.

Novel biophysical tools allow the structural dynamics of proteins and the regulation of such dynamics by binding partners to be explored in unprecedented detail. Although this has provided critical insights into protein function, the means by which structural dynamics direct protein evolution remain poorly understood. Here, we investigated how proteins with a bilobed structure, composed of two related domains from the periplasmic-binding protein-like II domain family, have undergone divergent evolution, leading to adaptation of their structural dynamics.

Structural and biophysical characterization of the tandem substrate-binding domains of the ABC importer GlnPQ.

The ATP-binding cassette transporter GlnPQ is an essential uptake system that transports glutamine, glutamic acid and asparagine in Gram-positive bacteria. It features two extra-cytoplasmic substrate-binding domains (SBDs) that are linked in tandem to the transmembrane domain of the transporter. The two SBDs differ in their ligand specificities, binding affinities and their distance to the transmembrane domain.

An integrated transport mechanism of the maltose ABC importer.

ATP-binding cassette (ABC) transporters use the energy of ATP hydrolysis to transport a large diversity of molecules actively across biological membranes. A combination of biochemical, biophysical, and structural studies has established the maltose transporter MalFGK as one of the best characterized proteins of the ABC family. MalF and MalG are the transmembrane domains, and two MalKs form a homodimer of nucleotide-binding domains.

Escherichia coli can survive stress by noisy growth modulation.

Gene expression can be noisy, as can the growth of single cells. Such cell-to-cell variation has been implicated in survival strategies for bacterial populations. However, it remains unclear how single cells couple gene expression with growth to implement these strategies.

Evolutionary engineering improves tolerance for medium-chain alcohols in .

Background: Yeast-based chemical production is an environmentally friendly alternative to petroleum-based production or processes that involve harsh chemicals. However, many potential alcohol biofuels, such as -butanol, isobutanol and -hexanol, are toxic to production organisms, lowering the efficiency and cost-effectiveness of these processes. We set out to improve the tolerance of toward these alcohols.

Retro-inversal of intracellular selected β-amyloid-interacting peptides: implications for a novel Alzheimer's disease treatment.

The aggregation of β-amyloid (Aβ) into toxic oligomers is a hallmark of Alzheimer's disease pathology. Here we present a novel approach for the development of peptides capable of preventing amyloid aggregation based upon the previous selection of natural all-l peptides that bind Aβ1-42. Using an intracellular selection system, successful library members were further screened via competition selection to identify the most effective peptides capable of reducing amyloid levels.

Student use and pedagogical impact of a mobile learning application.

Mobile learning (m-learning) is a relevant innovation in teaching and learning in higher education. A mobile app called NutriBiochem was developed for use in biochemistry and nutrition education for students in a second year Biochemistry and Metabolism course. NutriBiochem was accessed through smartphones, tablets, or computers.

Imputing forest carbon stock estimates from inventory plots to a nationally continuous coverage.

The U.S. has been providing national-scale estimates of forest carbon (C) stocks and stock change to meet United Nations Framework Convention on Climate Change (UNFCCC) reporting requirements for years.

Identification of a D-glycero-D-manno-heptosyltransferase gene from Helicobacter pylori.

We have identified a Helicobacter pylori d-glycero-d-manno-heptosyltransferase gene, HP0479, which is involved in the biosynthesis of the outer core region of H. pylori lipopolysaccharide (LPS). Insertional inactivation of HP0479 resulted in formation of a truncated LPS molecule lacking an alpha-1,6-glucan-, dd-heptose-containing outer core region and O-chain polysaccharide.

A novel yeast expression system for the overproduction of quality-controlled membrane proteins.

Saturation of the cell's protein folding capacity and accumulation of inactive incompletely folded protein often accompanying the overexpression of membrane proteins (MPs) presents an obstacle to their efficient purification in a functional form for structural studies. We present a novel strategy for optimization of functional MP expression in Saccharomyces cerevisiae. This approach exploits the unfolded protein response (UPR) pathway, a stress signaling mechanism that senses the accumulation of unfolded proteins in the endoplasmic reticulum.