%0 Journal Article %A Wilcock, Diane %A Duncan, Stephen A. %A Traktman, Paula %A Zhang, Wei-Hong %A Smith, Geoffrey L. %T The vaccinia virus A40R gene product is a nonstructural, type II membrane glycoprotein that is expressed at the cell surface %D 1999 %J Journal of General Virology, %V 80 %N 8 %P 2137-2148 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-80-8-2137 %I Microbiology Society, %X Gene A40R from vaccinia virus (VV) strain Western Reserve has been characterized. The open reading frame (ORF) was predicted to encode a 159 amino acid, 18152 Da protein with amino acid similarity to C-type animal lectins and to the VV A34R protein, a component of extracellular enveloped virus (EEV). Northern blotting and S1 nuclease mapping showed that gene A40R is transcribed early during infection from a position 12 nucleotides upstream of the ORF, producing a transcript of approximately 600 nucleotides. Rabbit anti-sera were raised against bacterial fusion proteins containing parts of the A40R protein. These were used to identify an 18 kDa primary translation product and N- and O-glycosylated forms of 28, 35 and 38 kDa. The A40R proteins were detected early during infection, formed higher molecular mass complexes under non-reducing conditions and were present on the cell surface but absent from virions. The proteins partitioned with integral membrane proteins in Triton X-114. Canine pancreatic microsomal membranes protected in vitro-translated A40R from proteinase K digestion, suggesting the A40R protein has type II membrane topology. A mutant virus with the A40R gene disrupted after amino acid 50, so as to remove the entire lectin-like domain, and a revertant virus were constructed. Disruption of the A40R gene did not affect virus plaque size, in vitro growth rate and titre, EEV formation, or virus virulence in a murine intranasal model. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-80-8-2137