RNase probing of the leader mRNA structure in the absence or presence of L20 protein

Abstract

<p><b>Copyright information:</b></p><p>Taken from "Ribosomal protein L20 controls expression of the operon via a transcription attenuation mechanism"</p><p></p><p>Nucleic Acids Research 2007;35(5):1578-1588.</p><p>Published online 8 Feb 2007</p><p>PMCID:PMC1865079.</p><p>© 2007 The Author(s).</p> An leader transcript (nts 1–168) was subjected to cleavage by RNases V1 or T1. Where indicated purified L20 protein was added prior to RNase cleavage. () Cleavages by RNase V1 and RNase T1 are shown on the leader mRNA structure. Colors indicate the change in cleavage efficiency observed in the presence of L20: black (no change), red (increase), blue (decrease). The numbers next to the symbols locate the corresponding cleavages on the gels (boxes). Shaded and encircled nucleotides correspond to positions conserved at the L20-binding site on 23S rRNA as shown in . () Cleavages on an unlabeled transcript were detected by primer extension with labeled oligonucleotide HP697 (positions 168–141 on leader). () Cleavages on a 5′ labeled transcript were analyzed directly