View source for 9xtd


==E.coli delta lepA 30S ribosomal subunit class B, body domain==
<StructureSection load='9xtd' size='340' side='right'caption='[[9xtd]], [[Resolution|resolution]] 2.26&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9xtd]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9XTD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9XTD 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]] 2.26&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=2MG:2N-METHYLGUANOSINE-5-MONOPHOSPHATE'>2MG</scene>, <scene name='pdbligand=D2T:(3R)-3-(METHYLSULFANYL)-L-ASPARTIC+ACID'>D2T</scene>, <scene name='pdbligand=G7M:N7-METHYL-GUANOSINE-5-MONOPHOSPHATE'>G7M</scene>, <scene name='pdbligand=MA6:6N-DIMETHYLADENOSINE-5-MONOPHOSHATE'>MA6</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PSU:PSEUDOURIDINE-5-MONOPHOSPHATE'>PSU</scene></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=9xtd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9xtd OCA], [https://pdbe.org/9xtd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9xtd RCSB], [https://www.ebi.ac.uk/pdbsum/9xtd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9xtd 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> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The function of the highly conserved GTPase LepA, a homolog of elongation factor EF-G, remains unknown in translation. However, there is biochemical data that it implicates in the 30S ribosomal subunit biogenesis. Here, using cryo-electron microscopy, we characterized 30S subunits isolated from an Escherichia coli strain with a deleted lepA gene. The cryo-EM maps for âlepA 30S particles were divided into classes corresponding to consecutive assembly intermediates: from particles characterized by unformed helices h44/h45 of the central decoding center (CDR) and highly flexible head, through intermediates with a distorted CDR and a partial stabilization of the head, to near-mature 30S subunits with correctly docked h44 in the CDR, accessible 3' end of 16S rRNA for translation but significant flexibility in head domain. Cryo-EM analysis of DeltalepA 30S intermediates revealed that they predominantly proceed to nearly mature functional state and exhibit suboptimal flexibility in the head domain. This finding suggests that LepA likely contributes to the final proper stabilization of the 3' domain of the 30S subunit during ribosome assembly.

The Conserved GTPase LepA May Contribute to the Final Proper Stabilization of the 3' Domain of the 30S Subunit During Ribosome Assembly.,Kravchenko O, Maksimova E, Baymukhametov T, Eliseeva I, Stolboushkina E Int J Mol Sci. 2026 Jan 3;27(1):489. doi: 10.3390/ijms27010489. PMID:41516366<ref>PMID:41516366</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9xtd" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Baymukhametov TN]]
[[Category: Kravchenko OV]]
[[Category: Maksimova EM]]
[[Category: Stolboushkina EA]]