View source for 7oi0


==E.coli delta rbfA pre-30S ribosomal subunit class D==
<StructureSection load='7oi0' size='340' side='right'caption='[[7oi0]], [[Resolution|resolution]] 2.76&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7oi0]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_BW25113 Escherichia coli BW25113]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7OI0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7OI0 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.76&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7oi0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7oi0 OCA], [https://pdbe.org/7oi0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7oi0 RCSB], [https://www.ebi.ac.uk/pdbsum/7oi0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7oi0 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RS4_ECOLI RS4_ECOLI] One of two assembly initiator proteins for the 30S subunit, it binds directly to 16S rRNA where it nucleates assembly of the body of the 30S subunit.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref>   With S5 and S12 plays an important role in translational accuracy; many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations).<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref>   Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref>   Protein S4 is also a translational repressor protein, it controls the translation of the alpha-operon (which codes for S13, S11, S4, RNA polymerase alpha subunit, and L17) by binding to its mRNA.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref>   Also functions as a rho-dependent antiterminator of rRNA transcription, increasing the synthesis of rRNA under conditions of excess protein, allowing a more rapid return to homeostasis. Binds directly to RNA polymerase.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref> 
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== Publication Abstract from PubMed ==
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 Escherichia&nbsp;coli 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 A 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.

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.,Maksimova EM, Korepanov AP, Kravchenko OV, Baymukhametov TN, Myasnikov AG, Vassilenko KS, Afonina ZA, Stolboushkina EA Int J Mol Sci. 2021 Jun 7;22(11):6140. doi: 10.3390/ijms22116140. PMID:34200244<ref>PMID:34200244</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 7oi0" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribosome 3D structures|Ribosome 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli BW25113]]
[[Category: Large Structures]]
[[Category: Baymukhametov T]]
[[Category: Korepanov A]]
[[Category: Kravchenko O]]
[[Category: Maksimova E]]
[[Category: Stolboushkina E]]