High-throughput functional comparison of promoter and enhancer activities

Motifs differ in their intrinsic biases toward the generation of promoter versus enhancer activities. (A, top) Sequence design for tandem repeats of 32 motifs, each totaling 87 bp in length; (bottom) enhancer and promoter activities of motif tandem repeats. (B, top) Sequence design for spaced motif repeats, with 18 motifs and three spacer sequences, each totaling 87 bp in length; (bottom) enhancer and promoter activities of spaced motif sequences. The log₂ of enhancer activity is shown. Stars indicate at least twofold activity with significance in a one-sided Student's t-test (P < 0.05). Error bars are SEM of n = 3 biological replicates. Promoter and enhancer activities are defined as in Figure 2B.