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Title: Visualization of the herpes simplex virus portal in situ by cryo-electron tomography

Abstract

Herpes simplex virus type 1 (HSV-1), the prototypical herpesvirus, has an icosahedral nucleocapsid surrounded by a proteinaceous tegument and a lipoprotein envelope. As in tailed bacteriophages, the icosahedral symmetry of the capsid is broken at one of the 12 vertices, which is occupied by a dodecameric ring of portal protein, UL6, instead of a pentamer of the capsid protein, UL19. The portal ring serves as a conduit for DNA entering and exiting the capsid. From a cryo-EM reconstruction of capsids immuno-gold-labeled with anti-UL6 antibodies, we confirmed that UL6 resides at a vertex. To visualize the portal in the context of the assembled capsid, we used cryo-electron tomography to determine the three-dimensional structures of individual A-capsids (empty, mature capsids). The similarity in size and overall shape of the portal and a UL19 pentamer - both are cylinders of {approx} 800 kDa - combined with residual noise in the tomograms, prevented us from identifying the portal vertices directly; however, this was accomplished by a computational classification procedure. Averaging the portal-containing subtomograms produced a structure that tallies with the isolated portal, as previously reconstructed by cryo-EM. The portal is mounted on the outer surface of the capsid floor layer, with its narrow endmore » pointing outwards. This disposition differs from that of known phage portals in that the bulk of its mass lies outside, not inside, the floor. This distinction may be indicative of divergence at the level of portal-related functions other than its role as a DNA channel.« less

Authors:
 [1];  [1];  [1];  [2];  [1];  [3];  [4];  [4];  [5]
  1. Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Building 50, Rm 1517, MSC 8025, 50 South Drive, National Institutes of Health, Bethesda, MD 20892-8025 (United States)
  2. (United States)
  3. Department of Cell Biology, Washington University School of Medicine, St. Louis, MO 63110 (United States)
  4. Department of Microbiology and Cancer Center, University of Virginia Health System, Charlottesville, VA 22908 (United States)
  5. Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Building 50, Rm 1517, MSC 8025, 50 South Drive, National Institutes of Health, Bethesda, MD 20892-8025 (United States). E-mail: Alasdair_Steven@nih.gov
Publication Date:
OSTI Identifier:
20977021
Resource Type:
Journal Article
Resource Relation:
Journal Name: Virology; Journal Volume: 361; Journal Issue: 2; Other Information: DOI: 10.1016/j.virol.2006.10.047; PII: S0042-6822(06)00804-X; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ANTIBODIES; BACTERIOPHAGES; DNA; ELECTRON MICROSCOPY; HERPES SIMPLEX; LIPOPROTEINS; TOMOGRAPHY

Citation Formats

Cardone, Giovanni, Winkler, Dennis C., Trus, Benes L., Imaging Sciences Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892, Cheng, Naiqian, Heuser, John E., Newcomb, William W., Brown, Jay C., and Steven, Alasdair C. Visualization of the herpes simplex virus portal in situ by cryo-electron tomography. United States: N. p., 2007. Web. doi:10.1016/j.virol.2006.10.047.
Cardone, Giovanni, Winkler, Dennis C., Trus, Benes L., Imaging Sciences Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892, Cheng, Naiqian, Heuser, John E., Newcomb, William W., Brown, Jay C., & Steven, Alasdair C. Visualization of the herpes simplex virus portal in situ by cryo-electron tomography. United States. doi:10.1016/j.virol.2006.10.047.
Cardone, Giovanni, Winkler, Dennis C., Trus, Benes L., Imaging Sciences Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892, Cheng, Naiqian, Heuser, John E., Newcomb, William W., Brown, Jay C., and Steven, Alasdair C. Thu . "Visualization of the herpes simplex virus portal in situ by cryo-electron tomography". United States. doi:10.1016/j.virol.2006.10.047.
@article{osti_20977021,
title = {Visualization of the herpes simplex virus portal in situ by cryo-electron tomography},
author = {Cardone, Giovanni and Winkler, Dennis C. and Trus, Benes L. and Imaging Sciences Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892 and Cheng, Naiqian and Heuser, John E. and Newcomb, William W. and Brown, Jay C. and Steven, Alasdair C.},
abstractNote = {Herpes simplex virus type 1 (HSV-1), the prototypical herpesvirus, has an icosahedral nucleocapsid surrounded by a proteinaceous tegument and a lipoprotein envelope. As in tailed bacteriophages, the icosahedral symmetry of the capsid is broken at one of the 12 vertices, which is occupied by a dodecameric ring of portal protein, UL6, instead of a pentamer of the capsid protein, UL19. The portal ring serves as a conduit for DNA entering and exiting the capsid. From a cryo-EM reconstruction of capsids immuno-gold-labeled with anti-UL6 antibodies, we confirmed that UL6 resides at a vertex. To visualize the portal in the context of the assembled capsid, we used cryo-electron tomography to determine the three-dimensional structures of individual A-capsids (empty, mature capsids). The similarity in size and overall shape of the portal and a UL19 pentamer - both are cylinders of {approx} 800 kDa - combined with residual noise in the tomograms, prevented us from identifying the portal vertices directly; however, this was accomplished by a computational classification procedure. Averaging the portal-containing subtomograms produced a structure that tallies with the isolated portal, as previously reconstructed by cryo-EM. The portal is mounted on the outer surface of the capsid floor layer, with its narrow end pointing outwards. This disposition differs from that of known phage portals in that the bulk of its mass lies outside, not inside, the floor. This distinction may be indicative of divergence at the level of portal-related functions other than its role as a DNA channel.},
doi = {10.1016/j.virol.2006.10.047},
journal = {Virology},
number = 2,
volume = 361,
place = {United States},
year = {Thu May 10 00:00:00 EDT 2007},
month = {Thu May 10 00:00:00 EDT 2007}
}