Assemblages of simian virus 40 capsid proteins and viral DNA visualized by electron microscopy
- Department of Hematology, Hebrew University-Hadassah Medical School, 91120 Jerusalem (Israel)
- Charles University, Prague (Czech Republic)
SV40 assembles in the nucleus by addition of capsid proteins to the minichromosome. The VP1{sub 5}VP2/3 capsomer is composed of a pentamer of the major protein VP1 complexed with a monomer of a minor protein, VP2 or VP3. In the capsid, the capsomers are bound together via their flexible carboxy-terminal arms. Our previous studies suggested that the capsomers are recruited to the packaging signal ses via avid interaction with Sp1. During assembly Sp1 is displaced, allowing chromatin compaction. Here we investigated the interactions in vitro of VP1{sub 5}VP2/3 capsomers with the entire SV40 genome, using mutant VP1 deleted in the carboxy-arm that cannot assemble, but retains DNA-binding capacity. EM revealed that VP1{sub 5}VP2/3 complexes bind non-specifically at random locations around the DNA. Sp1 was absent from mature virions. The findings suggest that multiple capsomers attach simultaneously to the viral genome, increasing their local concentration, facilitating rapid, concerted assembly reaction and removal of Sp1.
- OSTI ID:
- 20979790
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 353, Issue 2; Other Information: DOI: 10.1016/j.bbrc.2006.12.038; PII: S0006-291X(06)02690-8; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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