Figure 1.

Bru protein and binding motifs. (A) Organization of Bru protein. The structure is shown schematically, to scale, with the three RRM RNA binding domains indicated. The subdomains of Bru used for selections, RRM1+2 and RRM3+, are shown. (B) Graphical representations of preferred binding motifs identified by in vitro selections. The height of each stack represents the information content at each nucleotide of the motif in bits. At top left is the predominant motif identified from the Bru selection. The other motifs were identified from the RRM3+ selection. (C) comparison of the BRe consensus sequence and similar motifs from the selections. (D) The 3′ UTRs of the indicated mRNAs are shown schematically, with motifs from the aptamer selections indicated. The full height bars are perfect matches to the motifs, while the half height bars have a single mismatch. The top five 3′ UTRs are of Bru target mRNAs, while the bottom two 3′ UTRs are from other mRNAs not known to be regulated by Bru.