The bzpR 5′ UTR sequence and plasmids used to test translational suppression.

A. A ‘to scale’ schematic of the seven uORFs within the bzpR 5′ UTR, color coded to correspond with panels B and C. B. The bzpR 5′ UTR sequence and the first nine codons (blue) of the coding region. The 5′ ends of the three primers, bzr-9, bzr-10, and bzr-5, used in RT-PCR to localize the transcriptional start site, are indicated. Transcription likely starts between the two underlined regions. The sequence shown was fused to the GFP gene in pbzpR-17. The italicized region, consisting only of the ribosome binding site and the first 9 codons, is the no-UTR control fused to the GFP and RFP genes in pbzpR-14 and to the RFP gene in pbzpR-17, -53, and -54. The larger font T and A in the first and last uORFs represent the fusion junction in the internal deletion constructs (pbzpR-53 and -54). C. Schematic diagram of the plasmids used to demonstrate suppression of translation by the bzpR 5′ UTR. A15 represents the actin 15 promoter driving transcription of each fusion. Thin blue lines represent the remaining portions of the plasmids, including transcriptional terminators and selectable drug resistance genes.