Summary information and primary citation
- PDB-id
-
8wid;
DSSR-derived features in text and
JSON formats
- Class
- ribosome
- Method
- cryo-EM (3.5 Å)
- Summary
- Cryo- em structure of mycobacterium smegmatis 30s
ribosomal subunit (body 2) of 70s ribosome, e- trna and
rafh.
- Reference
-
Kumar N, Sharma S, Kaushal PS (2024): "Cryo- EM
structure of the mycobacterial 70S ribosome in complex
with ribosome hibernation promotion factor RafH."
Nat Commun, 15, 638. doi:
10.1038/s41467-024-44879-y.
- 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
(HPF<sub>long</sub>), hibernates ribosome in
70S monosome form, whereas in other bacteria, the
HPF<sub>long</sub> 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
HPF<sub>long</sub> NTD. In contrast, the C-
terminus domain (CTD) of RafH, which is larger than the
HPF<sub>long</sub> 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
HPF<sub>long</sub> structures, interact mainly
with the anti-Shine Dalgarno sequence of the 16S rRNA.
