The optimum imaging of an object structure at the sub-angstrom length scale requires precise adjustment of the lens aberrations of a high-resolution instrument up to the fifth order. A least-squares optimization of defocus aberration C1, third-order spherical aberration C3, and fifth-order spherical aberration C5 yields two sets of aberration coefficients for strong phase contrast up to the inf...

A critical evaluation of the performance of X-ray refinement protocols using various energy functions is presented using the bovine pancreatic trypsin inhibitor (BPTI) protein. The four potential energy functions we explored include: (1) fully quantum mechanical calculations; (2) one based on an incomplete molecular mechanics (MM) energy function employed in the Crystallography and NMR System (...

Abstract Cracks are formed along the photolithographically pre-determined lines with extremely high yield and repeatability, when Cu clusters introduced between planarized Au thin films sequentially deposited on a PET substrate. These act as nanometer-sized spacers preventing formation of contiguous metallic bond adjacent layers which will render prepatterned-cracking impossible. While effectiv...

Background. HNF-1a is a transcription factor that regulates glucose metabolism by expression in various tissues. Aim. To dock potential ligands of HNF-1a using docking software in silico. Methods. We performed in silico studies using HNF-1a protein 2GYP·pdb and the following softwares: ISIS/Draw 2.5SP4, ARGUSLAB 4.0.1, and HEX5.1. Observations. The docking distances (in angstrom units: 1 angstr...

During protein synthesis, translational release factors catalyze the release of the polypeptide chain when a stop codon on the mRNA reaches the A site of the ribosome. The detailed mechanism of this process is currently unknown. We present here the crystal structures of the ribosome from Thermus thermophilus with RF1 and RF2 bound to their cognate stop codons, at resolutions of 5.9 Angstrom and...

Solid silicon monoxide is an amorphous material which has been commercialized for many functional applications. However, the amorphous structure of silicon monoxide is a long-standing question because of the uncommon valence state of silicon in the oxide. It has been deduced that amorphous silicon monoxide undergoes an unusual disproportionation by forming silicon- and silicon-dioxide-like regi...

Angstrom-scale fluidic channels are ubiquitous in nature and play an important role regulating cellular traffic, signaling, responding to stimuli. Synthetic angstrom now a reality with the emergence of several cutting-edge bottom-up top-down fabrication methods. In particular, use atomically thin 2D materials nanotubes as components build conduits has pushed limits scale. Here, we provide overv...

Proton pumps in the plasma membrane of plants and yeasts maintain the intracellular pH and membrane potential. To gain insight into the molecular mechanisms of proton pumping, we built an atomic homology model of the proton pump based on the 2.6 angstrom x-ray structure of the related Ca2+ pump from rabbit sarcoplasmic reticulum. The model, when fitted to an 8 angstrom map of the Neurospora pro...

(+)-Epi-biotin differs from (+)-biotin in the configuration of the chiral center at atom C2. This could lead to a difference in the mode of binding of (+)-epi-biotin to streptavidin, a natural protein receptor for (+)-biotin. Diffraction data were collected to a maximum of 0.85 Angstrom resolution for structural analysis of the complex of streptavidin with a sample of (+)-epi-biotin and refinem...