Structure and architecture of immature and mature murine leukemia virus capsids.

摘要: Retroviruses assemble and bud from infected cells in an immature form require proteolytic maturation for infectivity. The CA (capsid) domains of the Gag polyproteins a protein lattice as truncated sphere virion. Proteolytic cleavage induces dramatic structural rearrangements; subset cleaved subsequently assembles into mature core, whose architecture varies among retroviruses. Murine leukemia virus (MLV) is prototypical γ-retrovirus serves basis retroviral vectors, but structure MLV layer unknown. Here we have combined X-ray crystallography with cryoelectron tomography to determine structures layers within authentic viral particles. This reveals changes associated maturation, and, by comparison HIV-1, uncovers conserved variable features. In contrast most used assembly which adopts variable, multilayered morphologies does not closed structure. Unlike there similarity between protein–protein interfaces those layer, could be achieved through domain rotations that largely maintain hexameric interactions. Nevertheless, architectural change on indicates extensive disassembly reassembly are required core growth. morphology suggests wrapping genome sheets may sufficient protect ribonucleoprotein during cell entry.