Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, 106 91 Stockholm, Sweden; Science for Life Laboratory, Stockholm University, Box 1031, 171 21 Solna, Sweden. Electronic address:
Published: September 2015
AI Article Synopsis
Article Abstract
At what point during translation do proteins fold? It is well established that proteins can fold cotranslationally outside the ribosome exit tunnel, whereas studies of folding inside the exit tunnel have so far detected only the formation of helical secondary structure and collapsed or partially structured folding intermediates. Here, using a combination of cotranslational nascent chain force measurements, inter-subunit fluorescence resonance energy transfer studies on single translating ribosomes, molecular dynamics simulations, and cryoelectron microscopy, we show that a small zinc-finger domain protein can fold deep inside the vestibule of the ribosome exit tunnel. Thus, for small protein domains, the ribosome itself can provide the kind of sheltered folding environment that chaperones provide for larger proteins.
Background: The decision to place a subcutaneously tunneled catheter is an infection prevention strategy for long term venous access allowing the proceduralist to access a vein and relocate the catheter exit site to a region on the body where care and maintenance can be safely performed. Subcutaneously tunneled centrally inserted dialysis catheter (ST-CIDC) placement is commonly performed in patients with renal disease and is traditionally performed with fluoroscopy in the interventional radiology suite or the operating theater. However, today's interventional radiologists and surgeons perform advanced invasive procedures that can be time-consuming resulting in delays in the scheduling of elective tunneled catheter placements.
Photodissociation of the CH2Cl radical is investigated by using high-level multireference configuration interaction ab initio methods, including the spin-orbit coupling. All possible fragmentation pathways, namely, CH2Cl + hν → CH2 + Cl, HCCl + H, and CCl + H2, have been analyzed. The potential-energy curves of the ground and several excited electronic states along the corresponding dissociating bond distance of each pathway have been calculated.
Land-based mazes that require spatial cues to identify the location of a hiding-place are a low-stress method to evaluate learning rate and memory retention in mice. One version, the Barnes maze, allows quantification of naturalistic exploratory behaviors not evident in water-based tasks. As the task relies on innate behaviors, it does not require overtraining, making it more feasible to examine early learning and non-memory executive functions that are characteristic of some non-amnestic dementias.
Phthalate diesters are important pollutants and act as endocrine disruptors. While certain bacterial esterases have been identified for phthalate diesters degradation to monoesters, their structural and mechanistic characteristics remain largely unexplored. Here, we highlight the potential of the thermostable and pH-tolerant EstS1 esterase from Sulfobacillus acidophilus DSM10332 to degrade high molecular weight bis(2-ethylhexyl) phthalate (DEHP) by combining biophysical and biochemical approaches along with high-resolution EstS1 crystal structures of the apo form and with bound substrates, products, and their analogs to elucidate its mechanism.
* A systematic review of 335 cases revealed that Mycobacterium abscessus was the most frequently identified pathogen, with many patients receiving treatment using multiple antibiotics.
* Early diagnosis using acid-fast bacilli staining and culture is crucial, and catheter removal may be necessary for effective management of these NTM infections.
