Figure 3.

RNA recognition elements determined by in vitro selection. RNA motifs determined by analysis of SELEX clone sequences are depicted for each RBP. The −log₁₀ P-values of the significance of motif enrichment in clones from the two distinct SELEX libraries (‘L1’ and ‘L2’) are represented in a red color scale. For each motif, the −log₁₀ P-value of the significance of genome-wide enrichment for motif sites in segments of its mRNA targets bound in vivo is also color-coded. Motifs are listed in the order they are discussed in the text. The gray box indicates data are not available because all L2 clones inadvertently contain an Hrb1 motif site in their 3′ constant region. Asterisks denote motifs that correspond to previously reported binding sites for the associated RBP. For exact data values and details see Supplementary Data S3.