10.6084/m9.figshare.7484534.v1 Kurata T. Kurata T. Nakanishi S. Nakanishi S. Hashimoto M. Hashimoto M. Taoka M. Taoka M. Isobe T. Isobe T. Kato J. Kato J. Supplementary Material for: Subunit Composition of Ribosome in the <b><i>yqgF</i></b> Mutant Is Deficient in pre-16S rRNA Processing of <b><i>Escherichia coli</i></b> Karger Publishers 2018 RNase Essential gene rRNA processing 16S rRNA Ribosomal protein S1 2018-12-19 11:17:02 Dataset https://karger.figshare.com/articles/dataset/Supplementary_Material_for_Subunit_Composition_of_Ribosome_in_the_b_i_yqgF_i_b_Mutant_Is_Deficient_in_pre-16S_rRNA_Processing_of_b_i_Escherichia_coli_i_b_/7484534 <i>Escherichia coli</i> 16S, 23S, and 5S ribosomal RNAs (rRNAs) are transcribed as a single primary transcript, which is subsequently processed into mature rRNAs by several RNases. Three RNases (RNase III, RNase E, and RNase G) were reported to function in processing the 5′-leader of precursor 16S rRNA (pre-16S rRNA). Previously, we showed that a novel essential YqgF is involved in that processing. Here we investigated the ribosome subunits of the <i>yqgF</i><sup>ts</sup> mutant by LC-MS/MS. The mutant ribosome had decreased copy numbers of ribosome protein S1, suggesting that the <i>yqgF</i> gene enables incorporation of ribosomal protein S1 into ribosome by processing of the 5′-end of pre-16S rRNA. The ribosome protein S1 is essential for translation in <i>E. coli</i>; therefore, our results suggest that YqgF converts the inactive form of newly synthesized ribosome into the active form at the final step of ribosome assembly.