Enzyme structure with two catalytic sites for double-sieve selection of substrate

High-fidelity transfers of genetic information in the central dogma can be achieved by a reaction called editing. The crystal structure of an enzyme with editing activity in translation is presented here at 2.5 angstroms resolution. The enzyme, isoleucyl-transfer RNA synthetase, activates not only the cognate substrate L-isoleucine but also the minimally distinct L-valine in the first, aminoacylation step. Then, in a second, "editing" step, the synthetase itself rapidly hydrolyzes only the valylated products. For this two-step substrate selection, a "double-sieve" mechanism has already been proposed. The present crystal structures of the synthetase in complexes with L-isoleucine and L-valine demonstrate that the first sieve is on the aminoacylation domain containing the Rossmann fold, whereas the second, editing sieve exists on a globular beta-barrel domain that protrudes from the aminoacylation domain.     

Automated 360° profilometry of a three-dimensional diffuse object and its reconstruction by use of the shading model

The 360° profilometry of a three-dimensional (3-D) diffuse object by use of the light intersection and its image reconstruction by surface shading are presented. The lack of data in one direction, which was due to occlusion, was compensated by the projection of two lines of light from different directions. Some experiments to profile objects and their reconstruction by computer are shown. The entire surface model was constructed, and a real shading image was obtained by means of computer graphics.     

A CMOS 1/spl times/-16/spl times/ speed DVD write channel IC

Optical recording demands a meticulous write strategy to control the laser beam power and regulate the phase change layer temperature tightly. The width, height, and delay of a string of short pulses applied to the laser diode need to be adjusted in fine steps, and the writing speed varies widely per applications. A multi-phase phase-locked loop (PLL) tracks a wide range of clock frequencies, and provides a low-jitter time base for write pulses. With two enabling circuit concepts, PLL loop filter voltage folding/unfolding and switch-in of parallel MOS resistors in delay cells, it is possible to operate a PLL to cover a frequency range spanning over three octaves with one VCO. A 10-stage differential VCO is phase-locked to the input channel clock ranging from 26 to 420 MHz (1/spl times/-16/spl times/ DVD speed), and its 20-phase outputs are used to generate write pulses. The pulsewidth and delay are programmed with 120 /spl plusmn/ 40 ps time resolution. The prototype chip fabricated in 0.35 /spl mu/m CMOS occupies 3.5/spl times/3.3 mm/sup 2/, and consumes 294 mW at 3.3 V.     

Advanced HSLA Steels for Automotive Use

Characteristic HSLA steels for automotive use are introduced in which both of precipitation and microstructure is controlled to obtain suitable mechanical properties.For outer panels such as fender,the combination of low yield strength,high tensile strength and deep-drawability were realized by controlling the distribution of NbC and precipitation free zone.The other steel,developed for chassis parts such as lower arm,utilizes extremely fine interphase precipitation to obtain high yield strength and excellent hole expansionability.Both steels have contributed to the reduction of weight in car body.     

GH-16 Type β-1,3-Glucanase from Lysobacter sp. MK9-1 Enhances Antifungal Activity of GH-19 Type Chitinase,and Its Glucan-binding Domain Binds to Fungal Cell-wall

The GH-16 type β-1,3-glucanase (BgluC16MK) gene of Lysobacter sp. MK9-1 was cloned to study its antifungal activities. BgluC16MK displays amino acid sequence similarity with GluC from L. enzymogenes strain N4-7. BgluC16MK includes a signal sequence, a catalytic domain and carbohydrate-binding module family 6-type β-glucan binding domain (B-GBD). The expression of the BgluC16MK gene in Escherichia coli without the signal sequence resulted in antifungal activity at a dose of 0.6-0.8 nmol/disk. However, BgluC16MK displayed antifungal activity at a dose of 0.025 nmol/disk in combination with Chi19MK. Substrate-specific assay revealed that purified BgluC16MK hydrolyzed insoluble curdlan more readily than the soluble substrate. Furthermore, to explore the binding selectivity of B-GBD of BgluC16MK, we constructed a fusion protein (B-GBD-GFP) using the B-GBD and green fluorescent protein. The activity of the fusion protein against various substrates indicates that B-GBD was selective for glucans with β-1,3-linkages. An additional study demonstrated the binding ability of B-GBD-GFP to the cell-wall of living fungi, such as T. reesei and Aspergillus oryzae. These findings suggest that BgluC16MK can be utilized to generate antifungal enzyme preparations and that the fusion protein B-GBD-GFP can be used to identify the fungal cell surface structure using β-glucans.     

A study of reactor neutrino monitoring at the experimental fast reactor JOYO

We carried out a study of neutrino detection at the experimental fast reactor JOYO using a 0.76 tons gadolinium loaded liquid scintillator detector. The detector was set up on the ground level at 24.3 m from the JOYO reactor core of 140 MW thermal power. The measured neutrino event rate from reactor on-off comparison was 1.11±1.24(stat.)±0.46(syst.) events/day. Although the statistical significance of the measurement was not enough, backgrounds in such a compact detector at the ground level were studied in detail and MC simulations were found to describe the data well. A study for improvement of the detector for future such experiments is also shown.