Previous Article | Next Article ![]()
Journal of Virology, March 2001, p. 2879-2890, Vol. 75, No. 6
Laboratory of Structural Biology, National
Institute of Arthritis, Musculoskeletal and Skin
Diseases,1 and Computational Bioscience
and Engineering Laboratory, Center for Information
Technology,2 National Institutes of
Health, Bethesda, Maryland 20892, and Department of
Microbiology,3 Department of Internal
Medicine,5 and Myles H. Thaler Center
for AIDS and Human Retrovirus Research,4
University of Virginia Health System, Charlottesville, Virginia
22908
Received 3 October 2000/Accepted 13 December 2000
The capsid of Kaposi's sarcoma-associated herpesvirus (KSHV) was
visualized at 24-Å resolution by cryoelectron microscopy. Despite limited sequence similarity between corresponding capsid proteins, KSHV has the same T=16 triangulation number and much the same
capsid architecture as herpes simplex virus (HSV) and cytomegalovirus
(CMV). Its capsomers are hexamers and pentamers of the major capsid
protein, forming a shell with a flat, close-packed, inner surface (the
"floor") and chimney-like external protrusions. Overlying the floor
at trigonal positions are (
0022-538X/01/$04.00+0 DOI: 10.1128/JVI.75.6.2879-2890.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Capsid Structure of Kaposi's Sarcoma-Associated
Herpesvirus, a Gammaherpesvirus, Compared to Those of an
Alphaherpesvirus, Herpes Simplex Virus Type 1, and a
Betaherpesvirus, Cytomegalovirus

2) heterotrimers called
triplexes. The floor structure is well conserved over all three
viruses, and the most variable capsid features reside on the outer
surface, i.e., in the shapes of the protrusions and triplexes, in which
KSHV resembles CMV and differs from HSV. Major capsid protein sequences
from the three subfamilies have some similarity, which is closer
between KSHV and CMV than between either virus and HSV. The triplex
proteins are less highly conserved, but sequence analysis identifies
relatively conserved tracts. In alphaherpesviruses, the
-subunit
(VP19c in HSV) has a 100-residue N-terminal extension and an insertion
near the C terminus. The small basic capsid protein sequences are
highly divergent: whereas the HSV and CMV proteins bind only to hexons,
difference mapping suggests that the KSHV protein, ORF65, binds around
the tips of both hexons and pentons.
*
Corresponding author. Mailing address: Bldg. 6, Rm.
B2-34, MSC 2717, National Institutes of Health, Bethesda, MD
20892-2717. Phone: (301) 496-0132. Fax: (301) 480-7629. E-mail:
Alasdair_Steven{at}nih.gov.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|