View source for 5kps


==Structure of RelA bound to ribosome in absence of A/R tRNA (Structure I)==
<SX load='5kps' size='340' side='right' viewer='molstar' caption='[[5kps]], [[Resolution|resolution]] 3.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5kps]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5KPS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5KPS 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]] 3.9&#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=5kps FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5kps OCA], [https://pdbe.org/5kps PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5kps RCSB], [https://www.ebi.ac.uk/pdbsum/5kps PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5kps ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/RS9_ECOLI RS9_ECOLI] The C-terminal tail plays a role in the affinity of the 30S P site for different tRNAs. Mutations that decrease this affinity are suppressed in the 70S ribosome.<ref>PMID:15308780</ref> 
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== Publication Abstract from PubMed ==
Stringent response is a conserved bacterial stress response underlying virulence and antibiotic resistance. RelA/SpoT-homolog proteins synthesize transcriptional modulators (p)ppGpp, allowing bacteria to adapt to stress. RelA is activated during amino-acid starvation, when cognate deacyl-tRNA binds to the ribosomal A (aminoacyl-tRNA) site. We report four cryo-EM structures of E. coli RelA bound to the 70S ribosome, in the absence and presence of deacyl-tRNA accommodating in the 30S A site. The boomerang-shaped RelA with a wingspan of more than 100 A wraps around the A/R (30S A-site/RelA-bound) tRNA. The CCA end of the A/R tRNA pins the central TGS domain against the 30S subunit, presenting the (p)ppGpp-synthetase domain near the 30S spur. The ribosome and A/R tRNA are captured in three conformations, revealing hitherto elusive states of tRNA engagement with the ribosomal decoding center. Decoding-center rearrangements are coupled with the step-wise 30S-subunit 'closure', providing insights into the dynamics of high-fidelity tRNA decoding.

Ribosome*RelA structures reveal the mechanism of stringent response activation.,Loveland AB, Bah E, Madireddy R, Zhang Y, Brilot AF, Grigorieff N, Korostelev AA Elife. 2016 Jul 19;5. pii: e17029. doi: 10.7554/eLife.17029. PMID:27434674<ref>PMID:27434674</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 5kps" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribosome 3D structures|Ribosome 3D structures]]
== References ==
<references/>
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[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Bah E]]
[[Category: Brilot AF]]
[[Category: Grigorieff N]]
[[Category: Korostelev AA]]
[[Category: Loveland AB]]
[[Category: Madireddy R]]
[[Category: Zhang Y]]