6BU8

70S ribosome with S1 domains 1 and 2 (Class 1)

This is a non-PDB format compatible entry.

Summary for 6BU8

• Entry DOI: 10.2210/pdb6bu8/pdb
• EMDB information: 7289
• Descriptor: 50S ribosomal protein L2, 50S ribosomal protein L14, 50S ribosomal protein L15, ... (60 entities in total)
• Functional Keywords: ribosome, trna, s1, ribosomal protein s1
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 60
• Total formula weight: 2312247.42

Authors

Loveland, A.B.,Korostelev, A.A. (deposition date: 2017-12-08, release date: 2018-01-31, Last modification date: 2020-01-01)

Primary citation

Loveland, A.B.,Korostelev, A.A.
Structural dynamics of protein S1 on the 70S ribosome visualized by ensemble cryo-EM.
Methods, 137:55-66, 2018

PubMed Abstract: Bacterial ribosomal protein S1 is the largest and highly flexible protein of the 30S subunit, and one of a few core ribosomal proteins for which a complete structure is lacking. S1 is thought to participate in transcription and translation. Best understood is the role of S1 in facilitating translation of mRNAs with structured 5' UTRs. Here, we present cryo-EM analyses of the 70S ribosome that reveal multiple conformations of S1. Based on comparison of several 3D maximum likelihood classification approaches in Frealign, we propose a streamlined strategy for visualizing a highly dynamic component of a large macromolecular assembly that itself exhibits high compositional and conformational heterogeneity. The resulting maps show how S1 docks at the ribosomal protein S2 near the mRNA exit channel. The globular OB-fold domains sample a wide area around the mRNA exit channel and interact with mobile tails of proteins S6 and S18. S1 also interacts with the mRNA entrance channel, where an OB-fold domain can be localized near S3 and S5. Our analyses suggest that S1 cooperates with other ribosomal proteins to form a dynamic mesh near the mRNA exit and entrance channels to modulate the binding, folding and movement of mRNA.

PubMed: 29247757
DOI: 10.1016/j.ymeth.2017.12.004

Experimental method

ELECTRON MICROSCOPY (3.5 Å)