7MSC

Mtb 70SIC in complex with MtbEttA at Pre_R0 state

This is a non-PDB format compatible entry.

Summary for 7MSC

• Entry DOI: 10.2210/pdb7msc/pdb
• EMDB information: 23961
• Descriptor: 50S ribosomal protein L32, 5S rRNA, 50S ribosomal protein L2, ... (59 entities in total)
• Functional Keywords: mycobacterium tuberculosis, abcf ribosome complex, antibiotic, ribosome
• Biological source: Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv); More
• Total number of polymer chains: 55
• Total formula weight: 2367164.18

Authors

Cui, Z.,Zhang, J. (deposition date: 2021-05-11, release date: 2022-02-02, Last modification date: 2024-05-29)

Primary citation

Cui, Z.,Li, X.,Shin, J.,Gamper, H.,Hou, Y.M.,Sacchettini, J.C.,Zhang, J.
Interplay between an ATP-binding cassette F protein and the ribosome from Mycobacterium tuberculosis.
Nat Commun, 13:432-432, 2022

PubMed Abstract: EttA, energy-dependent translational throttle A, is a ribosomal factor that gates ribosome entry into the translation elongation cycle. A detailed understanding of its mechanism of action is limited due to the lack of high-resolution structures along its ATPase cycle. Here we present the cryo-electron microscopy (cryo-EM) structures of EttA from Mycobacterium tuberculosis (Mtb), referred to as MtbEttA, in complex with the Mtb 70S ribosome initiation complex (70SIC) at the pre-hydrolysis (ADPNP) and transition (ADP-VO) states, and the crystal structure of MtbEttA alone in the post-hydrolysis (ADP) state. We observe that MtbEttA binds the E-site of the Mtb 70SIC, remodeling the P-site tRNA and the ribosomal intersubunit bridge B7a during the ribosomal ratcheting. In return, the rotation of the 30S causes conformational changes in MtbEttA, forcing the two nucleotide-binding sites (NBSs) to alternate to engage each ADPNP in the pre-hydrolysis states, followed by complete engagements of both ADP-VO molecules in the ATP-hydrolysis transition states. In the post-hydrolysis state, the conserved ATP-hydrolysis motifs of MtbEttA dissociate from both ADP molecules, leaving two nucleotide-binding domains (NBDs) in an open conformation. These structures reveal a dynamic interplay between MtbEttA and the Mtb ribosome, providing insights into the mechanism of translational regulation by EttA-like proteins.

PubMed: 35064151
DOI: 10.1038/s41467-022-28078-1

Experimental method

ELECTRON MICROSCOPY (2.97 Å)