Studies on the nucleocapsid structure of a group A arbovirus.
When Sindbis virus (273S) was treated with sodium desoxycholate, a nonhemagglutinating 136S particle was liberated from the virion, representing the viral nucleocapsid (core). Electron microscopically it appeared as a spherical particle 35 nm in diameter, showing ringlike morphological units 12 to 14 nm in diameter on its surface. When the one- and two-sided images of core particles were correlated, their structure could be demonstrated to have the T = 3 arrangement of 32 hexamer-pentamer morphological units within a symmetrical surface lattice. The core contained a further spherical structure (12 to 16 nm in diameter) which was designated as the central core component. Two proteins were found associated with the core, a third viral protein belonged to the hemagglutinating surface structures. The significance of these findings for virus classification is discussed.
D001103:Arboviruses / Q000032:analysis* / Q000145:classification / Q000302:isolation & purification; D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002621:Chemistry; D004586:Electrophoresis; D006387:Hemagglutination, Viral; D008854:Microscopy, Electron; D008961:Models, Structural; D013194:Staining and Labeling; D013997:Time Factors; D014461:Ultracentrifugation