The organization of potato virus X coat proteins in virus particles studied by tritium planigraphy and model building

• Published in: Virology (New York, N.Y.) Vol. 188; no. 1; pp. 175 - 180
• Main Authors: Baratova, L.A., Grebenshchikov, N.I., Dobrov, E.N., Gedrovich, A.V., Kashirin, I.A., Shishkov, A.V., Efimov, A.V., Järvekülg, L., Radavsky, Yu.L., Saarma, M.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.05.1992; Elsevier
• Subjects: Amino Acid Sequence; Biological and medical sciences; Capsid - chemistry; Fundamental and applied biological sciences. Psychology; Microbiology; Models, Molecular; Molecular Sequence Data; Morphology, structure, chemical composition, physicochemical properties; Nicotiana; Plant Viruses - chemistry; Plants, Toxic; potato virus X; POTEXVIRUS; Protein Conformation; PROTEINAS; PROTEINE; TECHNIQUE ANALYTIQUE; TECNICAS ANALITICAS; Tomography, X-Ray; Tritium; Virology; VIRUS DE LAS PLANTAS; VIRUS DES VEGETAUX; Plant pathogen; Tertiary structure; Potexvirus; Tritium; Subunit; Virus; Proteins; Virion; Potato virus X; Proton irradiation; Models; Capsid; Virus surface
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/0042-6822(92)90747-D

Potato virus X particles containing the intact, undegraded Ps form of the coat protein and particles containing the in situ degraded Pf form of the coat protein, which is devoid of 19–21 amino acids from the N-terminus, were bombarded with thermally activated tritium atoms, and the intramolecular distribution of the tritium label was studied. The tritium planigraphy revealed that the N-terminal region of the coat protein is the most accessible region for both type of PVX particles. The C-terminal region of the coat protein in the intact virus particles is almost inaccessible to the hot tritium atoms, whereas in Pf particles this region becomes available for the tritium label. A model of PVX coat protein tertiary structure was built, taking into account the predicted secondary structure of the protein, the principles of packing α-helices and β-structure in globular proteins, and known biochemical, immunological, and tritium bombardment data. In the model one β-sheet consisting of β-strands at regions 1–12, 14–22, and 24–33 flanks the molecule and forms the outside surface of the PVX particles.