Predicted sequence of UXP in Ad5, Ad1, and Ad2 as deduced from a cDNA clone of the Ad5 UXP mRNA. A549 cells were infected with 10 PFU/cell of Ad5. At 42 h p.i., cytoplasmic mRNA was isolated. Primers within the U exon and within the DBP-coding region were used to generate the cDNA corresponding to the putative UXP mRNA. The clone was sequenced to determine the splice sites and the Ad5 UXP protein sequence. The genomic sequences of Ad1 and Ad2 were then used to predict the amino acid sequence for UXP for these species C Ads. The predicted molecular masses are: 23,567.1 Da (Ad5), 23,509.2 Da (Ad2), and 22,697.1 Da (Ad1).