As the originator of the oxygen in our atmosphere, the photosynthetic water-splitting enzyme of chloroplasts is vital for aerobic life on the earth. It has a manganese cluster at its active site, but it is poorly understood at the molecular level. Polarized synchrotron radiation was used to examine the x-ray absorption of manganese in oriented chloroplasts. The manganese site, in the "resting" ...

The crystal structure of the double-stranded DNA bacteriophage HK97 mature empty capsid was determined at 3.6 angstrom resolution. The 660 angstrom diameter icosahedral particle contains 420 subunits with a new fold. The final capsid maturation step is an autocatalytic reaction that creates 420 isopeptide bonds between proteins. Each subunit is joined to two of its neighbors by ligation of the ...

The crystal structure of the arabinose-binding and dimerization domain of the Escherchia coli gene regulatory protein AraC was determined in the presence and absence of L-arabinose. The 1.5 angstrom structure of the arabinose-bound molecule shows that the protein adopts an unusual fold, binding sugar within a beta barrel and completely burying the arabinose with the amino-terminal arm of the pr...

We describe the crystal structure of the complete Thermus thermophilus 70S ribosome containing bound messenger RNA and transfer RNAs (tRNAs) at 5.5 angstrom resolution. All of the 16S, 23S, and 5S ribosomal RNA (rRNA) chains, the A-, P-, and E-site tRNAs, and most of the ribosomal proteins can be fitted to the electron density map. The core of the interface between the 30S small subunit and the...

First-principles calculations using density functional theory and two methods in comparison, Quantum ESPRESSO Siesta, are done on large supercells which describe different placements of identical adsorbed alkali metal atoms (of either Na, or K species) the monolayer boron carbide BC3. The energy single-atom adsorption over center C6 ring, C4B2 hexagon a atom have been preliminarily estimated, e...

Abstract We demonstrate the fabrication of surface nanoscale axial photonics bottle microresonators with angstrom precision using a flame. observe strongly unscalable behavior whispering gallery mode cutoff wavelengths different radial quantum numbers along fibre length.

Estimation of solar radiation is the most important parameter for various solar energy systems. Expensive devices are required to achieve the amount of solar radiation for a special region, therefore different models have been proposed by researchers to estimate the solar radiation that obviate using such devices. Nonlinear nature and excessive dependence on the meteorological parameters of the...

Cellulose is the major polysaccharide of plants where it plays a predominantly structural role. A variety of highly specialized microorganisms have evolved to produce enzymes that either synergistically or in complexes can carry out the complete hydrolysis of cellulose. The structure of the major cellobiohydrolase, CBHI, of the potent cellulolytic fungus Trichoderma reesei has been determined a...

The atomic structure of a SiGe/Si epitaxial interface grown via molecular beam epitaxy on a single crystal silicon substrate was investigated using an aberration-corrected scanning transmittance electron microscope equipped with a high-angle annular dark-field detector and an energy-dispersive spectrometer. The accuracy required for compensation of the various residual aberration coefficients t...

Mutations in the BRCA2 (breast cancer susceptibility gene 2) tumor suppressor lead to chromosomal instability due to defects in the repair of double-strand DNA breaks (DSBs) by homologous recombination, but BRCA2's role in this process has been unclear. Here, we present the 3.1 angstrom crystal structure of a approximately 90-kilodalton BRCA2 domain bound to DSS1, which reveals three oligonucle...