Autogenous regulation in vivo of the rpmE gene encoding ribosomal protein L31 (bL31), a key component of the protein–protein intersubunit bridge B1b

• DOI: 10.1261/rna.074237.119
• Publication Date: 2020-03-25T00:16:00Z
• Authors: Leonid V. Aseev; Ludmila S. Koledi...; Irina V. Boni
• Keywords: Ribosomal protein; Component (thermodynamics); Bridge (graph theory)

Bacterial ribosomal proteins (r-proteins) encoded by nonessential genes often carry out very important tasks in translation. In particular, this is the case of a small basic bacteria-specific r-protein L31 (bL31). Recent studies revealed crucial role bL31 formation protein–protein intersubunit bridge B1b and hence its contribution to ribosome dynamics. Our goal was study vivo regulation rpmE operon encoding bL31. We used previously developed approach based on chromosomally integrated fusions with lacZ reporter. E. coli transcribed from two promoter regions, translation both mRNA transcripts shown be feedback regulated bL31, indicating that autogenous operator located within shorter transcript. The bL31-mediated control gene-specific, as no found for -unrelated reporters. Thus, many other r-proteins, possesses dual activity living cells, acting an integral component repressor. Phylogenetic presence highly conserved stem–loop structure 5′UTR, presumable translational targeted which further confirmed site-directed mutagenesis. This stable separates AU-rich enhancer Shine-Dalgarno element, rare noncontiguous initiation region. Sequence/structure computational approaches classify RNA-binding protein, consistent repressor function discovered here. Mutational analysis showed unstructured amino-terminal part enriched lysine necessary activity.