Molecular basis of mRNA delivery to the bacterial ribosome

• 成果类型: Article
• 署名作者: Webster, Michael W.; Chauvier, Adrien; Rahil, Huma; Graziadei, Andrea; Charles, Kristine; Miropolskaya, Nataliya; Takacs, Maria; Saint-Andre, Charlotte; Rappsilber, Juri; Walter, Nils G.; Weixlbaumer, Albert
• 署名单位: Institut National de la Sante et de la Recherche Medicale (Inserm); Universites de Strasbourg Etablissements Associes; Universite de Strasbourg; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Biology (INSB); Institut National de la Sante et de la Recherche Medicale (Inserm); UK Research & Innovation (UKRI); Biotechnology and Biological Sciences Research Council (BBSRC); John Innes Center; University of Michigan System; University of Michigan; University of Michigan System; University of Michigan; Technical University of Berlin; University of Edinburgh
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10744
• DOI: 10.1126/science.ado8476
• 发表日期: 2024-11-29
• 关键词: protein s1; translation initiation; structural basis; DYNAMICS; subunits; polymerase; purification; sequence; platform; binding

摘要

Protein synthesis begins with the formation of a ribosome-messenger RNA (mRNA) complex. In bacteria, the small ribosomal subunit (30S) is recruited to many mRNAs through base pairing with the Shine-Dalgarno (SD) sequence and RNA binding by ribosomal protein bS1. Translation can initiate on nascent mRNAs, and RNA polymerase (RNAP) can promote the recruitment of the pioneering 30S. Here, we examined 30S recruitment to nascent mRNAs using cryo-electron microscopy, single-molecule fluorescence colocalization, and in-cell cross-linking mass spectrometry. We show that bS1 delivers the mRNA to the ribosome for SD duplex formation and 30S activation. Additionally, bS1 and RNAP stimulate translation initiation. Our work provides a mechanistic framework for how the SD duplex, ribosomal proteins, and RNAP cooperate in 30S recruitment to mRNAs and establish transcription-translation coupling.