Structure
Volume 6, Issue 11, 15 November 1998, Pages 1355-1367
Journal home page for Structure

Research Article
The structure of an insect parvovirus (Galleria mellonella densovirus) at 3.7 å resolution

https://doi.org/10.1016/S0969-2126(98)00136-1Get rights and content
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Abstract

Background: Parvoviruses infect vertebrates, insects and crustaceans. Many arthropod parvoviruses (densoviruses) are highly pathogenic and kill approximately 90% of the host larvae within days, making them potentially effective as selective pesticides. Improved understanding of densoviral structure and function is therefore desirable. There are four different initiation sites for translation of the densovirus capsid protein mRNA, giving rise to the viral proteins VP1 to VP4. Sixty copies of the common, C-terminal domain make up the ordered part of the icosahedral capsid.

Results: The Galleria mellonella densovirus (GMDNV) capsid protein consists of a core β-barrel motif, similar to that found in many other viral capsid proteins. The structure most closely resembles that of the vertebrate parvoviruses, but it has diverged beyond recognition in many of the long loop regions that constitute the surface features and intersubunit contacts. The N termini of twofold-related subunits have swapped their positions relative to those of the vertebrate parvoviruses. Unlike in the vertebrate parvoviruses, in GmDNV there is no continuous electron density in the channels running along the fivefold axes of the virus. Electron density corresponding to some of the single-stranded DNA genome is visible in the crystal structure, but it is not as well defined as in the vertebrate parvoviruses.

Conclusions: The sequence of the glycine-rich motif, which occupies each of the channels along the fivefold axes in vertebrate viruses, is conserved between mammalian and insect parvoviruses. This motif may serve to externalize the N-terminal region of the single VP1 subunit per particle. The domain swapping of the N termini between insect and vertebrate parvoviruses may have the effect of increasing capsid stability in GmDNV.

Keywords

domain swapping
evolution
Galleria mellonella
parvovirus
X-ray diffraction

Cited by (0)

AA Simpson, PR Chipman, TS Baker and MG Rossmann, Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1392, USA.

Present address for PR Chipman, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue, Seattle, WA 98109, USA.

P Tijssen, Institut Armand-Frappier, Université du Québec, 531 Boulevard des Prairies, Laval, Québec, Canada H7V 1B7.

E-mail address for MG Rossmann (corresponding author): [email protected].