title: Expression, crystallization and preliminary structural analysis of the ectoplasmic region of apical membrane antigen 1 from Plasmodium vivax, a malaria-vaccine candidate.
abstract: Apical membrane antigen 1 (AMA1), a type 1 transmembrane protein present in the microneme organelles of Plasmodium, is a leading malaria-vaccine candidate. The ectoplasmic region of AMA1 from P. vivax has been expressed in Pichia pastoris and crystallized in two different forms: an orthorhombic form (space group P2(1)2(1)2(1), unit-cell parameters a = 54.1, b = 76.1, c = 103.9 A) and a monoclinic form (space group C2, unit-cell parameters a = 150.0, b = 53.8, c = 60.3 A, beta = 113.2 degrees ). Native data have been collected to 2.0 A resolution for the orthorhombic form and 1.8 A for the monoclinic form. A platinum derivative was prepared for the orthorhombic and monoclinic crystals using K(2)PtCl(4) and data were collected at several wavelengths to obtain phases by the MAD technique. A partial model has been built from the electron-density maps of both forms and refinement is in progress.
authors.affiliation: Unité d'Immunologie Structurale, CNRS URA 2185, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Vulliez-Le Normand
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Pizarro
authors.forename: Marie Laure
authors.initials: ML
authors.lastname: Chesne-Seck
authors.forename: Clemens H M
authors.initials: CH
authors.lastname: Kocken
authors.forename: Bart
authors.initials: B
authors.lastname: Faber
authors.forename: Alan W
authors.initials: AW
authors.lastname: Thomas
authors.forename: Graham A
authors.initials: GA
authors.lastname: Bentley
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D003460:Crystallization; D018360:Crystallography, X-Ray; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics; D017780:Malaria Vaccines; D008565:Membrane Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D010966:Plasmodium vivax / Q000737:chemistry*; D015800:Protozoan Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000953:Antigens, Protozoan; D017780:Malaria Vaccines; D008565:Membrane Proteins; D015800:Protozoan Proteins; C090077:apical membrane antigen I, Plasmodium