This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Becker, M. N. Articles by Moyer, R. W. Search for Related Content PubMed PubMed Citation Articles by Becker, M. N. Articles by Moyer, R. W.

Amsacta moorei Entomopoxvirus Expresses an Active Superoxide Dismutase

Department of Molecular Genetics and Microbiology,¹ Department of Pharmacology,² Department of Pathology, University of Florida, Gainesville, Florida³

Received 23 January 2004/ Accepted 28 May 2004

The entomopoxvirus from Amsacta moorei serves as the prototype of the group B entomopoxviruses. One of the interesting genes found in Amsacta moorei entomopoxvirus (AmEPV) is a superoxide dismutase (sod) (open reading frame AMV255). Superoxide dismutases (SODs) catalyze the conversion of superoxide radicals to hydrogen peroxide and oxygen. Many vertebrate poxviruses contain a sod gene, but to date, none have been demonstrated to be active. There are three families of SODs, characterized by their metal ion-binding partners, Fe, Mn, or Cu and Zn. Poxvirus enzymes belong to the Cu-Zn SOD family. Unlike inactive vertebrate poxvirus SODs, AMVSOD contains all the amino acids necessary for function. We expressed and purified a 6X-His-tagged version of the AMVSOD in Escherichia coli. The recombinant AMVSOD demonstrates superoxide dismutase activity both in an in situ gel assay and by stopped flow spectrophotometry. The k_cat/K_m for AMVSOD is 4 x 10⁷ M^–1s^–1. In infected cells, the AMVSOD protein behaves as a dimer and is catalytically active; however, disruption of the gene in AMEPV has little or no effect on growth of the virus in cell culture. An analysis of mRNA expression indicates that AMVsod is expressed late during infection of Lymantria dispar (Ld652) cells and produces a discrete nonpolydisperse transcript. Characterization of protein expression with a monoclonal antibody generated against AMVSOD confirms that the AMVSOD protein can be classified as a late, postreplicative gene. Therefore, AMVSOD is the first example of an active poxvirus SOD.

This article has been cited by other articles:

• Teoh, M. L. T., Turner, P. V., Evans, D. H. (2005). Tumorigenic Poxviruses Up-Regulate Intracellular Superoxide To Inhibit Apoptosis and Promote Cell Proliferation. J. Virol. 79: 5799-5811 [Abstract] [Full Text]  
• Li, Q., Liston, P., Moyer, R. W. (2005). Functional Analysis of the Inhibitor of Apoptosis (iap) Gene Carried by the Entomopoxvirus of Amsacta moorei. J. Virol. 79: 2335-2345 [Abstract] [Full Text]