title: X-ray crystallographic analysis of pokeweed antiviral protein-II after reductive methylation of lysine residues.
abstract: Pokeweed antiviral protein II (PAP-II) is a naturally occurring protein isolated from early summer leaves of the pokeweed plant (Phytolacca americana). PAP-II belongs to a family of ribosome-inactivating proteins which catalytically deadenylate ribosomal and viral RNA. The chemical modification of PAP-II by reductive methylation of its lysine residues significantly improved the crystal quality for X-ray diffraction studies. Hexagonal crystals of the modified PAP-II, with unit cell parameters a = b = 92.51 A, c = 79.05 A, were obtained using 1.8 M Na/K phosphate as the precipitant. These crystals contained one enzyme molecule per asymmetric unit and diffracted up to 2.4 A, when exposed to a synchroton source.
authors.affiliation: Department of Structural Biology, Parker Hughes Institute, Roseville, Minnesota 55113, USA. igor@ih.org
authors.forename: I V
authors.initials: IV
authors.lastname: Kurinov
authors.forename: C
authors.initials: C
authors.lastname: Mao
authors.forename: J D
authors.initials: JD
authors.lastname: Irvin
authors.forename: F M
authors.initials: FM
authors.lastname: Uckun
mesh_terms: D018360:Crystallography, X-Ray; D008239:Lysine / Q000378:metabolism*; D008745:Methylation; D009699:N-Glycosyl Hydrolases; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D054789:Ribosome Inactivating Proteins, Type 1
chemical_list: D010940:Plant Proteins; D054789:Ribosome Inactivating Proteins, Type 1; D009699:N-Glycosyl Hydrolases; C024275:pokeweed antiviral protein; D008239:Lysine