Regulation of the expression of tufA and tufB, the 2 genes coding for the elongation factor EF-Tu in eschericia coli

Microbial Biotechnolog

National records of 3000 European bee and hoverfly species: A contribution to pollinator conservation

peer reviewedPollinators play a crucial role in ecosystems globally, ensuring the seed production of most flowering plants. They are threatened by global changes and knowledge of their distribution at the national and continental levels is needed to implement efficient conservation actions, but this knowledge is still fragmented and/or difficult to access. As a step forward, we provide an updated list of around 3000 European bee and hoverfly species, reflecting their current distributional status at the national level (in the form of present, absent, regionally extinct, possibly extinct or non-native). This work was attainable by incorporating both published and unpublished data, as well as knowledge from a large set of taxonomists and ecologists in both groups. After providing the first National species lists for bees and hoverflies for many countries, we examine the current distributional patterns of these species and designate the countries with highest levels of species richness. We also show that many species are recorded in a single European country, highlighting the importance of articulating European and national conservation strategies. Finally, we discuss how the data provided here can be combined with future trait and Red List data to implement research that will further advance pollinator conservation

Zone-interference gel electrophoresis: a new method for studying weak protein-nucleic acid complexes under native equilibrium conditions

A new and general electrophoresis method is described for the determination of dissociation constants of weak macromolecular complexes in the range of 10(-6) to 10(-4) M. The method is based on the measurement of the migration distance of a macromolecular complex in rapid dynamic equilibrium as a function of the interacting ligand concentration in a surrounding zone. Special advantages of the method are: its high sensitivity (dependent on the autoradiography, immunoblotting or staining technique used), its speed (electrophoresis time 20 min), and the independence of the Kd determination on the sample concentration of macromolecules. The latter is of great value for labile macromolecules: unknown partial inactivation does not influence the measurement. Studying the interactions between elongation factor EF-Tu and tRNA from E. coli we found for EF-Tu.GTP.aurodox.aminocyl-tRNA a Kd of 3 microM and for EF-Tu.GDP.aurodox.aminoacyl-tRNA a Kd of 11 microM at 9 degrees C

The three-dimensional folding of the tRNA-like structure of tobacco mosaic virus RNA. A new building principle applied twice

The structure of the tRNA-like 3' terminus of tobacco mosaic virus (TMV) RNA has been studied. A 3' -terminal fragment possessing the tRNA-like properties was probed with chemical modification and enzymatic digestions. A model of the secondary structure is proposed for the last 105 nucleotides. The corresponding region of other tobamoviral RNAs can be folded in an identical secondary structure. A three-dimensional model for the tRNA-like structure is given which is compared with those proposed earlier for the tRNA-like 3' termini of turnip yellow mosaic virus (TYMV) RNA and brome mosaic virus (BMV) RNA. A new building principle which we discovered previously by studying the latter RNAs appears to be applied twice in the tRNA-like structure of TMV RNA. The determination of the minimal length requirement for recognition of CTP, ATP:tRNA nucleotidyl-transferase reveals a size of ˜100 nucleotides in agreement with the models proposed