Structure of Cytoplasmic Polyhedrosis
Virus from Bombyx mori
YU Xue-Kui, LU Xin-Yin, ZHANG Hong, ZHOU Zhen-Hong, ZHANG
Qin-Fen, ZHANG Xing and ZHANG Jing-Qiang
( 1 State Key Lab for Biocontrol, Institute
of Entomology, ZhongShan University, Guangzhou 510275, China；2 University of
Texas-Houston Medical School, Houston, TX 77030, USA；3 Beijing Laboratory of
Electron Microscopy, Institute of Physics, Chinese Academy of Sciences, Beijing
100080, China )
Abstract The structures of full and
empty capsids of CPV were studied by negative staining and electron
cryomicroscopy and computer reconstruction techniques. By comparing the
structures and biochemical compositions, the CPV was identified as a single-layered
capsid with its five structural proteins located on it. This single capsid is
arranged according to T=1 icosahedral symmetry with 12 turret-like spikes at
its icosahedral vertices. The empty and full CPV show identical capsid but
differ inside. The dense and ordered genomic dsRNA is located inside the full
CPV. The internal space of the empty CPV has almost no electron density except
for 12 electron densities attributed the transcriptional enzyme complexes
extending inward from the base part of CPV spikes.
Key Words cytoplasmic polyhedrosis virus (CPV)； transcriptional complex； electron cryomicroscopy
Corresponding author:
Tel, 86-20-84112286; Fax, 86-20-84035279; e-mail, [email protected]