Summary information and primary citation
- PDB-id
-
7oi0;
DSSR-derived features in text and
JSON formats
- Class
- ribosome
- Method
- cryo-EM (2.76 Å)
- Summary
- E.coli delta rbfa pre-30s ribosomal subunit class
d
- Reference
-
Maksimova EM, Korepanov AP, Kravchenko OV, Baymukhametov
TN, Myasnikov AG, Vassilenko KS, Afonina ZA,
Stolboushkina EA (2021): "RbfA Is
Involved in Two Important Stages of 30S Subunit Assembly:
Formation of the Central Pseudoknot and Docking of Helix
44 to the Decoding Center." Int J Mol Sci,
22. doi: 10.3390/ijms22116140.
- Abstract
- Ribosome biogenesis is a highly coordinated and complex
process that requires numerous assembly factors that ensure
prompt and flawless maturation of ribosomal subunits.
Despite the increasing amount of data collected, the exact
role of most assembly factors and mechanistic details of
their operation remain unclear, mainly due to the shortage
of high-resolution structural information. Here, using
cryo-electron microscopy, we characterized 30S ribosomal
particles isolated from an
<i>Escherichia</i> <i>coli</i>
strain with a deleted gene for the RbfA factor. The cryo-EM
maps for pre-30S subunits were divided into six classes
corresponding to consecutive assembly intermediates: from
the particles with a completely unresolved head domain and
unfolded central pseudoknot to almost mature 30S subunits
with well-resolved body, platform, and head domains and
partially distorted helix 44. The structures of two
predominant 30S intermediates belonging to most populated
classes obtained at 2.7 Å resolutions indicate that RbfA
acts at two distinctive 30S assembly stages: early
formation of the central pseudoknot including folding of
the head, and positioning of helix 44 in the decoding
center at a later stage. Additionally, it was shown that
the formation of the central pseudoknot may promote
stabilization of the head domain, likely through the
RbfA-dependent maturation of the neck helix 28. An update
to the model of factor-dependent 30S maturation is
proposed, suggesting that RfbA is involved in most of the
subunit assembly process.
