Analysis of t4 endonuclease v homologs from a variety of chlorella virus strains

T4 endonuclease V is a UV damage-specific DNA glycosylase, which recognizes cyclobutane pyriraidine dimers. The poor solubility of the enzyme has hindered its structural analysis, therefore finding a homolog of endonuclease V with better biophysical properties has been of major interest to our group. Recently the first homolog for T4 endonuclease V was identified by Lu et al.( Virology 206:339-352). A 4.5kb fragment of the Chlorella virus strain PBCV-1 was sequenced and a 426 bp fragment has been identified (A SOL), which encodes a predicted amino acid sequence 41% identical to that of endonuclease V. Blot hybridization of different Chlorella virus DNAs has shown that most of the DNAs will hybridize with the A50L gene. In this study, we used the polymerase chain reaction to amplify the endonuclease V homolog gene from several Chlorella virus genomic DNAs, that are either: 1.) geographically distinct (isolated from Brazil, China, Russia, Australia, Israel and various locations in Europe and the United States); or 2.) distinct based on the level of methylation of cytosine(ranging from 1 to 45% methylation). The DNA fragments were then isolated and cloned into a TA vector for sequencing. Sequence alignment analysis will be presented.