Crystallization and preliminary crystallographic analysis of the major capsid proteins VP16 and VP17 of bacteriophage P23-77

摘要

Members of the diverse double--barrel lineage of viruses are identified by theconserved structure of their major coat protein. New members of this lineagehave been discovered based on structural analysis and we are interested inidentifying relatives that utilize unusual versions of the double--barrel fold.One candidate for such studies is P23-77, an icosahedral dsDNA bacteriophagethat infects the extremophile Thermus thermophilus. P23-77 has two major coatproteins, namely VP16 and VP17, of a size consistent with a single--barrel corefold. These previously unstudied proteins have now been successfully expressedas recombinant proteins, purified and crystallized using hanging-drop andsitting-drop vapour-diffusion methods. Crystals of coat proteins VP16 and VP17have been obtained as well as of a putative complex. In addition, virus-derivedmaterial has been crystallized. Diffraction data have been collected to beyond3 A˚ resolution for five crystal types and structure determinations are in progress.1