Third-degree burns associated with transcutaneous pacing.

A 69-year-old severely obese diabetic woman developed nausea, vomiting and diarrhoea which caused multiple metabolic alterations leading to hypotension and bradycardia due to slow atrioventricular junctional rhythm. Transcutaneous pacing (TCP) was initiated and maintained until the underlying heart rate and blood pressure normalised. TCP gel pads were kept in place prophylactically after pacing was terminated.

Observing cellulose biosynthesis and membrane translocation in crystallo.

Many biopolymers, including polysaccharides, must be translocated across at least one membrane to reach their site of biological function. Cellulose is a linear glucose polymer synthesized and secreted by a membrane-integrated cellulose synthase. Here, in crystallo enzymology with the catalytically active bacterial cellulose synthase BcsA-BcsB complex reveals structural snapshots of a complete cellulose biosynthesis cycle, from substrate binding to polymer translocation.

A molecular description of cellulose biosynthesis.

Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge.

Bicelles coming of age: an empirical approach to bicelle crystallization.

Biological membranes represent a unique environment in which integral membrane proteins (MPs) fold to perform diverse biological functions. In many cases, lipids support the native conformation or mediate important interactions between MPs. It is therefore imperative to develop methods that maintain this support for the structural and functional analyses of an exceedingly important class of biological macromolecules.

Mechanism of activation of bacterial cellulose synthase by cyclic di-GMP.

The bacterial signaling molecule cyclic di-GMP (c-di-GMP) stimulates the synthesis of bacterial cellulose, which is frequently found in biofilms. Bacterial cellulose is synthesized and translocated across the inner membrane by a complex of cellulose synthase BcsA and BcsB subunits. Here we present crystal structures of the c-di-GMP-activated BcsA-BcsB complex.

Crystallographic snapshot of cellulose synthesis and membrane translocation.

Cellulose, the most abundant biological macromolecule, is an extracellular, linear polymer of glucose molecules. It represents an essential component of plant cell walls but is also found in algae and bacteria. In bacteria, cellulose production frequently correlates with the formation of biofilms, a sessile, multicellular growth form.