EMD-51618

Composite map
Single-particle
3.5 Å
EMD-51618 Deposition: 20/09/2024
Map released: 20/11/2024
Last modified: 11/12/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-51618

30S mRNA delivery complex TEC resolved (30S only)

EMD-51618

Composite map
Single-particle
3.5 Å
EMD-51618 Deposition: 20/09/2024
Map released: 20/11/2024
Last modified: 11/12/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Escherichia coli K-12, synthetic construct
Sample: 30S ribosomal subunit
Fitted models: 9gus (Avg. Q-score: 0.401)

Deposition Authors: Rahil H , Weixlbaumer A , Webster MW
Molecular basis of mRNA delivery to the bacterial ribosome.
PUBMED: 39607923
DOI: doi:10.1126/science.ado8476
ISSN: 1095-9203
ASTM: SCIEAS
Abstract:
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.