Comparative mechanistic studies of de novo RNA synthesis by flavivirus RNA-dependent RNA polymerases

Flavivirus protein NS5 harbors the RNA-dependent RNA polymerase (RdRp) activity. In contrast to the RdRps of hepaci- and pestiviruses, which belong to the same family of Flaviviridae, NS5 carries two activities, a methyltransferase (MTase) and a RdRp. RdRp domains of Dengue virus (DV) and West Nile virus (WNV) NS5 were purified in high yield relative to full-length NS5 and showed full RdRp activity. Steady-state enzymatic parameters were determined on homopolymeric template poly(rC). The presence of the MTase domain does not affect the RdRp activity. Flavivirus RdRp domains might bear more than one GTP binding site displaying positive cooperativity. The kinetics of RNA synthesis by four Flaviviridae RdRps were compared. In comparison to Hepatitis C RdRp, DV and WNV as well as Bovine Viral Diarrhea virus RdRps show less rate limitation by early steps of short-product fort-nation. This suggests that they display a higher conformational flexibility upon the transition from initiation to elongation. (c) 2006 Elsevier Inc. All rights reserved.

La Chiesa in Australia: Cattolici Sottosopra=The Church in Australia: Catholics Sottosopra

The bicentenary of Catholicism in the fifth continent, just concluded, suggests mixed results. Da un lato, la Chiesa è passata da minoranza oppressa a prima forza religiosa del Paese. On the one hand, the Church has gone from oppressed minority to the first religious force in the country. Ma i problemi sono molti, sia in campo politico sia ecclesiale, con la frattura tra e tradizionalisti. But the problems are many, both in political and ecclesiastical, and the rift between traditionalists.