In Vitro Assembly of Virus-Like Particles of a Gammaretrovirus, the Murine Leukemia Virus XMRV

作者：Hadravova Romana; de Marco Alex; Ulbrich Pavel; Stokrova Jitka; Dolezal Michal; Pichova Iva; Ruml Tomas; Briggs John A G; Rumlova Michaela^*

来源：Journal of Virology, 2012, 86(3): 1297-1306.

DOI：10.1128/JVI.05564-11

Immature retroviral particles are assembled by self-association of the structural polyprotein precursor Gag. During maturation the Gag polyprotein is proteolytically cleaved, yielding mature structural proteins, matrix (MA), capsid (CA), and nucleocapsid (NC), that reassemble into a mature viral particle. Proteolytic cleavage causes the N terminus of CA to fold back to form a beta-hairpin, anchored by an internal salt bridge between the N-terminal proline and the inner aspartate. Using an in vitro assembly system of capsid-nucleocapsid protein (CANC), we studied the formation of virus-like particles (VLP) of a gammaretrovirus, the xenotropic murine leukemia virus (MLV)-related virus (XMRV). We show here that, unlike other retroviruses, XMRV CA and CANC do not assemble tubular particles characteristic of mature assembly. The prevention of beta-hairpin formation by the deletion of either the N-terminal proline or 10 initial amino acids enabled the assembly of Delta ProCANC or Delta 10CANC into immature-like spherical particles. Detailed three-dimensional (3D) structural analysis of these particles revealed that below a disordered N-terminal CA layer, the C terminus of CA assembles a typical immature lattice, which is linked by rod-like densities with the RNP.

• 出版日期2012-2