Identification and characterization of the simian varicella virus uracil DNA glycosylase

Simian varicella virus (SVV) infection of non-human primates is used as a model to study the pathogenesis and latency of varicella-zoster virus (VZV), the etiological agent of chickenpox and shingles. Uracil DNA glycosylase (UDG) is a DNA repair enzyme responsible for excision of uracil residues misincorporated into DNA. UDG is conserved throughout the herpesvirus family and may play an important role in viral pathogenesis. This study identified a 300 amino acid SVV UDG that shares 53.9% amino acid identity with the VZV UDG. The SVV UDG is expressed in infected Vero cells as determined by reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot analysis. The SVV UDG is encoded on a 2.0 kb transcript which also appears to encode the SVV glycoprotein L (gL) and the VZV gene 58 homolog. The SVV UDG is enzymatically active as determined by the ability of a SVV UDG-maltose binding protein fusion construct to remove [(3)H]-uracil incorporated into DNA.