A Single Missense Mutation in a Coiled-Coil Domain of Escherichia coli Ribosomal Protein S2 Confers a Thermosensitive Phenotype That Can Be Suppressed by Ribosomal Protein S1

• DOI: 10.1128/jb.01305-12
• Publication Date: 2012-10-29T13:43:17Z
• Authors: Leonid V. Aseev; Anton O. Chugunov; Roman G. Efremov; Irina V. Boni
• Keywords: Ribosomal protein; Ribosomal binding site; 30S

Ribosomal protein S2 is an essential component of translation machinery, and its viable mutated variants conferring distinct phenotypes serve as a valuable tool in studying the role regulation. One few available rpsB mutants, rpsB1, shows thermosensitivity ensures enhanced expression leaderless mRNAs. In this study, we identified nature rpsB1 mutation. Sequencing allele revealed G-to-A transition part gene which encodes coiled-coil domain S2. The resulting E132K substitution resides highly conserved site, TKKE, so-called N-terminal capping box, at beginning second alpha helix. protruding known to provide binding with 16S rRNA head 30S subunit and, addition, interact key mRNA protein, S1. Molecular dynamics simulations detrimental impact mutation on structure thereby interactions between rRNA, providing clue for mutant. Using strain producing lacZ transcript from chromosomal lac promoter, demonstrated that not only generating S2/S1-deficient ribosomes but also rpsA::IS10 leading partial deficiency S1 alone increased efficiency by about 10-fold. Moderate overexpression relieved all these effects moreover, suppressed thermosensitive phenotype indicating extragenic suppressor