Details

Autor(en) / Beteiligte

• Yeager, Mark
• Wilson-Kubalek, Elizabeth M.
• Weiner, Scott G.
• Brown, Patrick O.
• Rein, Alan

Titel

Supramolecular Organization of Immature and Mature Murine Leukemia Virus Revealed by Electron Cryo-Microscopy: Implications for Retroviral Assembly Mechanisms

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 1998-06, Vol.95 (13), p.7299-7304

Ort / Verlag

United States: National Academy of Sciences of the United States of America

Erscheinungsjahr

1998

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• We have used electron cryo-microscopy and image analysis to examine the native structure of immature, protease-deficient (PR-) and mature, wild-type (WT) Moloney murine leukemia virus (MuLV). Maturational cleavage of the Gag polyprotein by the viral protease is associated with striking morphological changes. The PR-MuLV particles exhibit a rounded central core, which has a characteristic track-like shell on its surface, whereas the WT MuLV cores display a polygonal surface with loss of the track-like feature. The pleomorphic shape and inability to refine unique orientation angles suggest that neither the PR-nor the WT MuLV adheres to strict icosahedral symmetry. Nevertheless, the PR-MuLV particles do exhibit paracrystalline order with a spacing between Gag molecules of ≈ 45 angstrom and a length of ≈ 200 angstrom. Because of the pleomorphic shape and paracrystalline packing of the Gag-RNA complexes, we raise the possibility that assembly of MuLV is driven by protein-RNA, as well as protein-protein, interactions. The maturation process involves a dramatic reorganization of the packing arrangements within the ribonucleoprotein core with disordering and loosening of the individual protein components.