Increased selectivity of directed RNA hydrolysis mediated by RNAse H from E. coli using mixed oligo(deoxyribo-ribo)nucleotides

Chimeric oligo(deoxyribo-ribo)nucleotides appeared to be a valuable tool to achieve the high selectivity of RNA cleavage as shown by RNA-ase H-mediated hydrolysis of TMV RNA directed by d(TGTGTATGCC), d(TGTGTAT), d(TGTGTAT)GCCAU and d(TGTGTAT)ppGCCAU.     

Pili (fimbriae) of the causative agents of plague and pseudotuberculosis: their detection in the hemagglutination reaction, the passive hemagglutination reaction and in an immunoenzyme analysis system

Newly developed serological methods for the detection of pili in the passive hemagglutination (PHA) test with the use of immunoglobulin erythrocytic diagnosticum and in the enzyme immunoassay (EIA) with the use of specific immunoglobulins labeled with horse radish peroxidase have been found to exceed the method of detecting pili, based on the determination of their hemagglutinating activity, in sensitivity and specificity. Besides, the PHA test and EIA have proved to be capable of detecting low molecular fragments of pili, obtained by sonication and having lost their hemagglutinating activity.     

Ethylene Production and Activation of Hydrolytic Enzymes during Acclimation of Maize Seedlings to Partial Flooding

The effects of partial flooding on the partial pressure of oxygen and carbon dioxide in water around the roots, ethylene production by intact maize (Zea mays L.) seedlings, the activities of hydrolytic enzymes (pectinase, xylanase, and cellulase) in adventitious roots, and the growth of adventitious and main roots were studied. Aggravated hypoxia resulted in the accelerated ethylene production and the activation of enzymes destroying cell walls in the adventitious roots; as a result, the latter changed their growth pattern. The conclusion is that the interrelated responses are adaptive ones, and the adventitious roots play a key role in plant adaptation.     

Regulation of RNA translation in potato virus X RNA-coat protein complexes: The key role of the N-terminal segment of the protein

The efficiency of in vitro translation of the potato virus X (PVX) RNA was studied for viral ribonucleoprotein complexes (vRNP) assembled from the genomic RNA and the viral coat protein (CP). In vRNP particles the 5′-proximal RNA segments were encapsidated into the CP, which formed helical headlike structures differing in length. Translation of the PVX RNA was completely suppressed upon incubation with PVX CP and was activated within vRNPs assembled in vitro with two CP forms, differing in the modification of the N-terminal peptide containing the main phosphorylation site(s) for Thr/Ser protein kinases. It was shown that CP phosphorylation activates RNA translation within vRNPs and that the removal of the N-terminal peptide of CP suppresses activation, but CP still acts as a translational suppressor. This fact made it possible to suppose that the replacement of Ser/Thr by amino acid residues that are not subject to phosphorylation in the N-terminal peptide of CP of the mutant PVX (PVX-ST) completely inhibits RNA translation within vRNP. However, experiments disproved this assumption: PVX-ST RNA was efficiently translated within native virions, RNA of the wild-type (wt) PVX was efficiently translated in heterogeneous vRNP (wtRNA + PVX-ST CP), and the opposite result (repression of translation) was obtained for another heterogeneous vRNP (PVX-ST RNA + wtCP). Therefore, the N-terminal CP peptide located on the surface of the PVX virion or vRNP particles plays a key role in the activation of viral RNA translation.