Nucleotide sequence of a cytomegalovirus single-stranded DNA-binding protein gene: comparison with alpha- and gammaherpesvirus counterparts reveals conserved segments.

The genomic sequence encoding a cytomegalovirus strain Colburn homologue (DB129) of the herpes simplex virus major DNA-binding protein (ICP8) was determined. Multiple alignments of the deduced DB129 amino acid sequence and three alpha- and gammaherpesvirus homologues revealed that 56% of the amino acid residues identical in all four homologues are contained within 12 relatively conserved segments, which together constitute only 11.2% of the shortest aligned sequence. In light of published ICP8 deletion analyses, this alignment suggests conserved segments that may participate in forming DNA contacts. The identified conserved regions present interesting targets for site-directed mutagenesis in structure-function analyses.