EMD-37565

Single-particle
2.9 Å
EMD-37565 Deposition: 24/09/2023
Map released: 28/02/2024
Last modified: 28/02/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-37565

Cryo- EM structure of Mycobacterium smegmatis 30S ribosomal subunit (body 2) of 70S ribosome and RafH.

EMD-37565

Single-particle
2.9 Å
EMD-37565 Deposition: 24/09/2023
Map released: 28/02/2024
Last modified: 28/02/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Mycolicibacterium smegmatis MC2 155
Sample: 70S ribosome + RafH protein
Fitted models: 8wif (Avg. Q-score: 0.564)

Deposition Authors: Kumar N , Sharma S, Kaushal PS
Cryo- EM structure of the mycobacterial 70S ribosome in complex with ribosome hibernation promotion factor RafH.
Kumar N , Sharma S, Kaushal PS
(2024) Nat Commun , 15 , 638 - 638
PUBMED: 38245551
DOI: doi:10.1038/s41467-024-44879-y
ISSN: 2041-1723
Abstract:
Ribosome hibernation is a key survival strategy bacteria adopt under environmental stress, where a protein, hibernation promotion factor (HPF), transitorily inactivates the ribosome. Mycobacterium tuberculosis encounters hypoxia (low oxygen) as a major stress in the host macrophages, and upregulates the expression of RafH protein, which is crucial for its survival. The RafH, a dual domain HPF, an orthologue of bacterial long HPF (HPFlong), hibernates ribosome in 70S monosome form, whereas in other bacteria, the HPFlong induces 70S ribosome dimerization and hibernates its ribosome in 100S disome form. Here, we report the cryo- EM structure of M. smegmatis, a close homolog of M. tuberculosis, 70S ribosome in complex with the RafH factor at an overall 2.8 Å resolution. The N- terminus domain (NTD) of RafH binds to the decoding center, similarly to HPFlong NTD. In contrast, the C- terminus domain (CTD) of RafH, which is larger than the HPFlong CTD, binds to a distinct site at the platform binding center of the ribosomal small subunit. The two domain-connecting linker regions, which remain mostly disordered in earlier reported HPFlong structures, interact mainly with the anti-Shine Dalgarno sequence of the 16S rRNA.