Fig. 1.

Construction of KSHV-lyt. (A) Schematic illustration of KSHV BAC36 mutagenesis. ORF50 exon 1 and ORF49 were first replaced by a zeo cassette. ORF49 was then reinserted in reverse orientation together with a PGK promoter and ORF50 exon 1. The kan cassette flanked by FRT sites (black ovals) was subsequently removed with FLP recombinase. Nucleotide positions refer to GenBank accession no. HQ404500. (B) XbaI restriction pattern of the parental and mutant BAC genomes in an ethidium bromide-stained agarose gel. For better visibility, images of the upper and lower parts of the gel were taken separately. Fragments affected by mutagenesis as predicted in panel A are indicated by arrowheads.