News

Exposing Hidden Alternative Backbone Conformations in X-ray Crystallography Using qFit

Describing the multiple conformations of proteins is important for understanding the relationship between molecular flexibility and function. However, most methods for interpreting data from X-ray crystallography focus on building a single structure of the protein, which limits the potential for biological insights. Here we introduce an improved algorithm for using crystallographic data to model these multiple conformations that addresses two previously overlooked types of protein backbone flexibility: peptide flips and glycine movements.

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De novo phasing with X-ray laser reveals mosquito larvicide BinAB structure

BinAB is a naturally occurring paracrystalline larvicide distributed worldwide to combat the devastating diseases borne by mosquitoes. These crystals are composed of homologous molecules, BinA and BinB, which play distinct roles in the multi-step intoxication process, transforming from harmless, robust crystals, to soluble protoxin heterodimers, to internalized mature toxin, and finally to toxic oligomeric pores.

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Structural enzymology using X-ray free electron lasers

Mix-and-inject serial crystallography (MISC) is a technique designed to image enzyme catalyzed reactions in which small protein crystals are mixed with a substrate just prior to being probed by an X-ray pulse. This approach offers several advantages over flow cell studies. It provides (i) room temperature structures at near atomic resolution, (ii) time resolution ranging from microseconds to seconds, and (iii) convenient reaction initiation. It outruns radiation damage by using femtosecond X-ray pulses allowing damage and chemistry to be separated.

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Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

For several decades, X-ray crystallography has been the dominant technique to solve the three-dimensional (3D) structure of biological macromolecules at atomic resolution. Structures of proteins, protein complexes and the machinery of entire biological reaction pathways have been elucidated, leading to numerous breakthroughs in our understanding of molecular architecture and function. However, not every protein complex crystallizes, a necessary condition for investigation using these methods.

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Job Opening: Research Specialist

Arizona State University is currently seeking a research specialist. This position in experimental biophysics would assist scientists in collecting experimental data at the Linac Coherent Light Source (LCLS) X-ray laser near Stanford University, as part of the BioXFEL project . The job is based at ASU but there will be travel to the LCLS several times a year. This position would also assist in fabrication of sample delivery devices in the biophysics laboratories of the BioXFEL program.

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Three-dimensional-printed gas dynamic virtual nozzles for x-ray laser sample delivery

Reliable sample delivery is essential to biological imaging using X-ray Free Electron Lasers (XFELs). Continuous injection using the Gas Dynamic Virtual Nozzle (GDVN) has proven valuable, particularly for time-resolved studies. However, many important aspects of GDVN functionality have yet to be thoroughly understood and/or refined due to fabrication limitations. We report the application of 2-photon polymerization as a form of high-resolution 3D printing to fabricate high-fidelity GDVNs with submicron resolution.

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