FIG. 1.
The mRNAs transcribed from the UL24 locus. (A) Schematic representation of the HSV-1 genome (prototype arrangement) indicating the location of the UL24 gene at map coordinate 0.3. The major repeat sequences are represented by the open rectangles that flank the unique long (UL) and unique short (US) regions as shown. The UL24 locus is diagrammed below the HSV-1 genome. The three UL24 promoters are indicated by arrows numbered 1, 2, and 3 and are located at nucleotides 47402, 47666, and 48076 relative to the HSV-1 strain 17 sequence (34). Positions of the UL24 ORF (open rectangle) and of the UL24 and UL26 poly(A) sites are shown. (B) Locations of the six mRNAs transcribed from the UL24 locus. Solid circles represent the 5′ cap, thin lines represent the 5′ and 3′ UTRs, the solid box represents the UL24 ORF, and the poly(A) tail is indicated by arrowheads. The thicker lines in the 1.4-, 5.6-, 0.9-, and 5.2-kb transcripts are reflective of the strengths of promoters 1 and 3, which are stronger than promoter 2. The molecular lengths of the transcripts are indicated to the left of the transcripts; the temporal gene classes for the 1.4-, 5.6-, 0.9-, and 5.2-kb transcripts are indicated at the right; the temporal gene class for the 5.4- and 1.2-kb transcripts has not been determined conclusively due to their low abundance.