Hexameric helicases and translocases are required for numerous essential nucleic-acid transactions. To better understand the mechanisms by which these enzymes recognize target substrates and use nucleotide hydrolysis to power molecular movement, we have determined the structure of the Rho transcription termination factor, a hexameric RNA/DNA helicase, with single-stranded RNA bound to the motor...

some kinetic properties of nad+- and nadp+- dependent glucose 6-phosphatedehydrogenase (g6pd) purified from streptomyces aureofaciens were studied. both nadh andnadph inhibited the enzyme competitively and noncompetitively, with respect to the correspondingcoenzymes and glucose 6-phosphate, respectively. atp inhibited the nad+ - linked reaction but not thatof the nadp+- linked activity. the inh...

the voltammetric behaviour of sulfadoxine (sdn) was studied at a glassy carbon electrode in 0.2 m phosphate buffer solutions using cyclic, differential-pulse (dpv) and square wave voltammetry (swv). the dependence of the current on ph, concentration, and scan rate was investigated to optimize the experimental conditions for the determination of sdn. the oxidation process was shown to be diffusi...

in order to evaluate the effect of balanced application of chemical phosphorus fertilizer and seed inoculation with phosphate solubilizing bacterium and arbuscular mycorrhizal fungus and on the yield and yield components of maize (zea mays l.) under normal and limited irrigation conditions, a split-split plots arrangement based on randomized complete block design with three replications was con...

Mannose 6-phosphate-specific receptors with an apparent molecular mass of 215,000 are present in fibroblasts at the cell surface and in intracellular membranes. The cell surface receptors mediate endocytosis of exogenous lysosomal enzymes and exchange with the intracellular receptors, which function in the sorting of endogenous lysosomal enzymes. In the present study, several methods independen...

We have used Chinese hamster ovary (CHO) cells and a murine lymphoma cell line to study the recycling of the 215-kD and the 46-kD mannose 6-phosphate receptors to various regions of the Golgi to determine the site where the receptors first encounter newly synthesized lysosomal enzymes. For assessing return to the trans-most Golgi compartments containing sialyltransferase (trans-cisternae and tr...

Directional cell movement in response to external chemical gradients requires establishment of front-rear asymmetry, which distinguishes an up-gradient protrusive leading edge, where Rac-induced F-actin polymerization takes place, and a down-gradient retractile tail (uropod in leukocytes), where RhoA-mediated actomyosin contraction occurs. The signals that govern this spatial and functional asy...

The formation of virus movement protein (MP)-containing punctate structures on the cortical endoplasmic reticulum is required for efficient intercellular movement of Red clover necrotic mosaic virus (RCNMV), a bipartite positive-strand RNA plant virus. We found that these cortical punctate structures constitute a viral replication complex (VRC) in addition to the previously reported aggregate s...