Kaspar Hollenstein

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ATP-binding cassette (ABC) transporter proteins carry diverse substrates across cell membranes. Whereas clinically relevant ABC exporters are implicated in various diseases or cause multidrug resistance of cancer cells, bacterial ABC importers are essential for the uptake of nutrients, including rare elements such as molybdenum. A detailed understanding of(More)
Structural analysis of class B G-protein-coupled receptors (GPCRs), cell-surface proteins that respond to peptide hormones, has been restricted to the amino-terminal extracellular domain, thus providing little understanding of the membrane-spanning signal transduction domain. The corticotropin-releasing factor receptor type 1 is a class B receptor which(More)
BtuCD is an adenosine triphosphate-binding cassette (ABC) transporter that translocates vitamin B12 from the periplasmic binding protein BtuF into the cytoplasm of Escherichia coli. The 2.6 angstrom crystal structure of a complex BtuCD-F reveals substantial conformational changes as compared with the previously reported structures of BtuCD and BtuF. The(More)
ATP-binding cassette (ABC) transporters are ubiquitous membrane proteins that couple the transport of diverse substrates across cellular membranes to the hydrolysis of ATP. The crystal structures of four ABC transporters have recently been determined. They reveal similar arrangements of the conserved ATP-hydrolyzing nucleotide-binding domains, but unrelated(More)
Methylxanthines, including caffeine and theophylline, are among the most widely consumed stimulant drugs in the world. These effects are mediated primarily via blockade of adenosine receptors. Xanthine analogs with improved properties have been developed as potential treatments for diseases such as Parkinson's disease. Here we report the structures of a(More)
ATP-binding cassette (ABC) transporters are integral membrane proteins that move diverse substrates across cellular membranes. ABC importers catalyse the uptake of essential nutrients from the environment, whereas ABC exporters facilitate the extrusion of various compounds, including drugs and antibiotics, from the cytoplasm. How ABC transporters couple ATP(More)
Potent, ligand efficient, selective, and orally efficacious 1,2,4-triazine derivatives have been identified using structure based drug design approaches as antagonists of the adenosine A(2A) receptor. The X-ray crystal structures of compounds 4e and 4g bound to the GPCR illustrate that the molecules bind deeply inside the orthosteric binding cavity. In vivo(More)
Class B GPCRs of the secretin family are important drug targets in many human diseases including diabetes, neurodegeneration, cardiovascular disease and psychiatric disorders. X-ray crystal structures for the glucagon receptor and corticotropin-releasing factor receptor 1 have now been published. In this review, we analyse the new structures and how they(More)
Risk assessments for natural hazards are becoming more widely used and accepted. Using an extended definition of risk, it becomes obvious that performant procedures for vulnerability assessments are vital for the success of the risk concept. However, there are large gaps in knowledge about vulnerability. To alleviate the situation, a conceptual extension of(More)
Bacteria and archaea import molybdenum and tungsten from the environment in the form of the oxyanions molybdate (MoO4 2−) and tungstate (WO4 2−). These substrates are captured by an external, high-affinity binding protein, and delivered to ATP binding cassette transporters, which move them across the cell membrane. We have recently reported a crystal(More)