Adenylate kinases have an M(r) around 23,000 which classifies them among the smallest phosphoryl group transferring enzymes. In order to prevent phosphoryl transfer to water, i.e. hydrolysis, these enzymes undergo induced-fit motions on substrate binding and assemble/disassemble their catalytic centres during each reaction cycle. Details of these processes have been derived from several X-ray s...

The Fe2+ ion that specifically replaces Mg2+ in the active center of RNA polymerase generates reactive hydroxyl radicals that cause highly localized cleavage of polypeptide chains. Mapping of the cleavage sites revealed the overall architecture of the active center. Nine distinct sites, five in the beta subunit and four in the beta' subunit of Escherichia coli RNA polymerase, all at or near hig...

Using modular arithmetic we introduce a simple bound which applies to a wide range of bin-packing like problems. This bound must hold if a problem is to be soluble. When it fails, search can therefore be pruned. We show the value of such pruning in a greedy backtracking algorithm for number partitioning problems. As the bound can be used when solving inexact as well as exact partitioning proble...

Core-based system-on-chips (SoCs) fabricated on three-dimensional (3D) technology are emerging for better integration capabilities. Effective test architecture design and optimization techniques are essential to minimize the manufacturing cost for such gigascale integrated circuits. Test-access mechanisms (TAMs) and test wrappers (e.g., the IEEE Standard 1500 wrapper) facilitate the modular tes...

The Gram-positive bacterium Paenibacillus sp. str. FPU-7 effectively hydrolyzes chitin by using a number of chitinases. A unique chitinase with two catalytic domains, ChiW, is expressed on the cell surface of this bacterium and has high activity towards various chitins, even crystalline chitin. Here, the crystal structure of ChiW at 2.1 Å resolution is presented and describes how the enzyme deg...

The mycobacterial cell wall presents significant challenges to mycobacteriophages--viruses that infect mycobacterial hosts--because of its unusual structure containing a mycolic acid-rich mycobacterial outer membrane attached to an arabinogalactan layer that is in turn linked to the peptidoglycan. Although little is known about how mycobacteriophages circumvent these barriers during the process...

The industrial methane steam reforming reaction usually employs particulate catalyst that are easy to prepare and cost-effective, but suffer from problems such as high reactor pressure drop low overall utilization. In this study, the Ni-Al 2 CaO 4 powder prepared by equal volume impregnation method was subjected particle size control using a pressing method, made into particles of different siz...

Phosphorylation sites are formed by protein kinases ('writers'), frequently exert their effects following recognition by phospho-binding proteins ('readers') and are removed by protein phosphatases ('erasers'). This writer-reader-eraser toolkit allows phosphorylation events to control a broad range of regulatory processes, and has been pivotal in the evolution of new functions required for the ...