TABLE 2.

Transcriptional effect of sequences downstream of the C boxes

Downstream enda	pvuIIC alleleb	CAT activityc
		Absolute	Normalized
−24	WT	271 ± 20	0.03
	Esp19	748 ± 23	0.08
+88	WT	8,998 ± 1,117	1.00
	Esp19	514 ± 44	0.06

^aThe number of nucleotides from the native pvuII sequence between the C boxes and the reporter gene cloning junction. In both cases, the 5′ endpoints are −93 (relative to the pvuIIC initiation codon). The 3′ endpoints correspond to +3 and +114, respectively, relative to the previously reported promoter (60). In all cases, the consensus C boxes are present in the context of an otherwise WT pvuIIC sequence. In the longer clones, a short substitution immediately downstream of the 3′-most C box generates a restriction site used for clone assembly; substitutions in this area were found not to affect transcription (see text).

^bC.PvuII is supplied in trans from either the WT allele or a mutant inactive allele in which an extra codon has been inserted within the predicted HTH motif.

^cCAT activity was measured as described in Materials and Methods and is expressed (± the standard error) as mean counts per minute incorporated per minute per microgram of protein from triplicate samples. The vector control levels (not shown) were subtracted as background.