Infectious Myonecrosis Virus Has a Totivirus-Like, 120-Subunit Capsid, but with Fiber Complexes at the Fivefold Axes
Infectious myonecrosis virus (IMNV) is an emerging pathogen of penaeid shrimp in global aquaculture. Tentatively assigned to family Totiviridae, it has a nonsegmented dsRNA genome of 7,560 bp and an isometric capsid of the 901-aa major capsid protein. We used electron cryomicroscopy and 3D image rec...
Saved in:
Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 105; no. 45; pp. 17526 - 17531 |
---|---|
Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
11.11.2008
National Acad Sciences |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Infectious myonecrosis virus (IMNV) is an emerging pathogen of penaeid shrimp in global aquaculture. Tentatively assigned to family Totiviridae, it has a nonsegmented dsRNA genome of 7,560 bp and an isometric capsid of the 901-aa major capsid protein. We used electron cryomicroscopy and 3D image reconstruction to examine the IMNV virion at 8.0-Å resolution. Results reveal a totivirus-like, 120-subunit T = 1 capsid, 450 Å in diameter, but with fiber complexes protruding a further 80 Å at the fivefold axes. These protrusions likely mediate roles in the extracellular transmission and pathogenesis of IMNV, capabilities not shared by most other totiviruses. The IMNV structure is also notable in that the genome is centrally organized in five or six concentric shells. Within each of these shells, the densities alternate between a dodecahedral frame that connects the threefold axes vs. concentration around the fivefold axes, implying certain regularities in the RNA packing scheme. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Author contributions: J.T., W.F.O., R.S.S., B.T.P., D.V.L., T.S.B., and M.L.N. designed research; J.T., W.F.O., R.S.S., B.T.P., D.V.L., T.S.B., and M.L.N. performed research; J.T., R.S.S., B.T.P., D.V.L., and T.S.B. contributed new reagents/analytic tools; J.T., W.F.O., R.S.S., B.T.P., S.A.G., D.V.L., T.S.B., and M.L.N. analyzed data; and J.T., R.S.S., S.A.G., D.V.L., T.S.B., and M.L.N. wrote the paper. Edited by Reed B. Wickner, National Institutes of Health, Bethesda, MD, and approved September 18, 2008 2Present address: Marine Phage Laboratory, Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721 1Present address: Electron Microscopy Facility, Burnham Institute for Medical Research, La Jolla, CA 92037. |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.0806724105 |