Crystallization of the MS2 translational repressor alone and complexed to bromouridine

Journal ArticleThe coat protein from the MS2 bacteriophage plays a dual role by encapsidating viral RNA and also by binding RNA as a translational repressor. In order to study the isolated dimer in a conformation not influenced by capsid interactions, a mutant molecule was crystallized that is defective in capsid assembly but is an active repressor. The unassembled dimer crystallized in the space group P21212 with a = 76.2, b = 55.7, and c = 28.4 A. In these crystals, monomers were related by twofold symmetry. When this dimer was co-crystallized with 5-bromouridine, crystals formed in space group R3 with a = b = 155.9 A, c = 29.9 A, gamma = 120 degrees; the dimer was the asymmetric unit

Effects of polymer additives in the bulk of turbulent thermal convection

We present experimental evidence that a minute amount of polymer additives can significantly enhance heat transport in the bulk region of turbulent thermal convection. The effects of polymer additives are found to be the \textit{suppression} of turbulent background fluctuations that give rise to incoherent heat fluxes that make no net contribution to heat transport, and at the same time to \textit{increase} the coherency of temperature and velocity fields. The suppression of small-scale turbulent fluctuations leads to more coherent thermal plumes that result in the heat transport enhancement. The fact that polymer additives can increase the coherency of thermal plumes is supported by the measurements of a number of local quantities, such as the extracted plume amplitude and width, the velocity autocorrelation functions and the velocity-temperature cross-correlation coefficient. The results from local measurements also suggest the existence of a threshold value for the polymer concentration, only above which can significant modification of the plume coherent properties and enhancement of the local heat flux be observed. Estimation of the plume emission rate suggests that the second effect of polymer additives is to stabilize the thermal boundary layers.Comment: 8 figures, 11 page

Characterization of Wave Propagation in Thin Laminated Plates

This is an electronic version of an article published in Du, C., Ni, Q. & Natsuki, T. (2010). Characterization of Wave Propagation in Thin Laminated Plates. [Materials and Manufacturing Processes is available online at: http://www.informaworld.com/smpp/content~db=all?content=10.1080/10426910903426349The formulae including the in-plane stiffness and bending stiffness coefficients and coupling effect in out-plane were presented for analyzing characterization of wave propagation. Using the present formulae, the wave velocities can be calculated in any case of laminated plates including nonsymmetric lamination. In this study, the characteristics of wave propagation in thin laminated plates were investigated in detail. Five modes including symmetric modes and antisymmetric modes were obtained from the proposed formulae. For each mode, the wave velocities of laminated plates were investigated in different conditions such as plate thickness, stacking sequence, and vibrational frequency.ArticleMATERIALS AND MANUFACTURING PROCESSES. 25(4):259-263 (2010)journal articl

Bis(1,10-phenanthroline-κ2 N,N′)(sulfato-κ2 O,O′)nickel(II) propane-1,3-diol solvate

In the structure of the title compound, [Ni(SO4)(C12H8N2)2]·C3H8O2, the NiII ion (site symmetry 2) is six-coordinated in a distorted octa­hedral manner by four N atoms from two chelating 1,10-phenanthroline (phen) ligands and two O atoms from a bidentate sulfate ligand (2 symmetry). The dihedral angle between the two chelating NCCN groups is 80.9 (1)°. The central C atom of the propane-1,3-diol solvent mol­ecule is likewise located on a twofold rotation axis. In the crystal structure, the [Ni(SO4)(C12H8N2)2] and C3H8O2 entities are connected through inter­molecular O—H⋯O hydrogen bonding

Identification of a locus involved in the utilization of iron by Actinobacillus pleuropneumoniae

The cloned afu locus of Actinobacillus pleuropneumoniae restored the ability of an Escherichia coli K-12 mutant (aroB) to grow on iron-limited media. DNA sequence analysis of the fragment showed that there are three genes designated afuA, afuB and afuC (Actinobacillus ferric uptake) that encode products similar to the SfuABC proteins of Serratia marcescens, the HitABC proteins of Haemophilia influenzae, the FbpABC proteins of Neisseria gonorrhoeae and the YfuABC proteins of Yersinia enterocolitica. The three genes encode a periplasmic iron-binding protein (AfuA), a highly hydrophobic integral cytoplasmic membrane protein with two consensus permease motifs (AfuB) and one hydrophilic peripheral cytoplasmic membrane protein with Walker ATP-binding motifs (AfuC), respectively. This system has been shown to constitute a periplasmic binding protein-dependent iron transport system in these organisms. The afuABC operon is locating approximately 200 bp upstream of apxIC gene, but transcribed in opposite direction to the ApxI-toxin gene