Lymphocytic choriomeningitis virus. V. Proposed structural arrangement of proteins in the virion

Abstract

Previous work by M.J. Buchmeier and his colleagues and by our group has led to the conclusion that the lymphocytic choriomeningitis (LCM) virus contains seven distinct structural proteins, which we have named p200, gp85, p77, p63, gp60, gp44, and gp35. Their arrangement in the virion has now been analysed by establishing nearest-neighbour relationships with a homobifunctional crosslinker, by performing polyacrylamide gel electrophoresis in parallel under reducing and non-reducing conditions, and by determining the proteins that are covalently bound to viral lipids. A hypothetical model of the virion of LCM virus is proposed. Its envelope is assumed to consist of a membranous layer composed of gp60 and lipids and two types of spikes with either gp85 or gp44 as tips and gp35 as bases. The last-mentioned glycoprotein also appears to be complexed with p63, the main protein component of the nucleocapsid, and this in turn was found to be spatially associated with p200. Probably p77 is also an internal component, but a more exact position cannot yet be assigned to this protein.