FIG. 1.

Deletion analysis of the promoter-regulatory region flanking oriS. At the top of the figure is a diagram of the 822-bp intergenic region between the divergently transcribed genes encoding ICP4 and ICP22/47. This region contains oriS and the promoter-regulatory elements of these two immediate-early genes. The long black rectangle represents the 80-bp minimum oriS sequence that consists of an AT-rich stretch (white bow tie) at the center of an imperfect palindrome and three binding sites (I, II, and III) for OBP and OBPC. Other symbols designate individual cis-acting elements in the oriS-flanking region. The extent of oriS-flanking sequences in the wild-type plasmid pOS 822 and the remaining sequences in deletion constructs are represented as black lines. The replication efficiency of each plasmid in transient DNA replication assays is shown to the right of the name of the plasmid. The results from at least three experiments per plasmid were averaged and normalized against the replication efficiency of pOS 822.