View source for 6q97


==Structure of tmRNA SmpB bound in A site of E. coli 70S ribosome==
<SX load='6q97' size='340' side='right' viewer='molstar' caption='[[6q97]], [[Resolution|resolution]] 3.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6q97]] 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=6Q97 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6Q97 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='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=0TD:(3S)-3-(METHYLSULFANYL)-L-ASPARTIC+ACID'>0TD</scene>, <scene name='pdbligand=1MG:1N-METHYLGUANOSINE-5-MONOPHOSPHATE'>1MG</scene>, <scene name='pdbligand=2MA:2-METHYLADENOSINE-5-MONOPHOSPHATE'>2MA</scene>, <scene name='pdbligand=2MG:2N-METHYLGUANOSINE-5-MONOPHOSPHATE'>2MG</scene>, <scene name='pdbligand=3TD:(1S)-1,4-ANHYDRO-1-(3-METHYL-2,4-DIOXO-1,2,3,4-TETRAHYDROPYRIMIDIN-5-YL)-5-O-PHOSPHONO-D-RIBITOL'>3TD</scene>, <scene name='pdbligand=4OC:4N,O2-METHYLCYTIDINE-5-MONOPHOSPHATE'>4OC</scene>, <scene name='pdbligand=5MC:5-METHYLCYTIDINE-5-MONOPHOSPHATE'>5MC</scene>, <scene name='pdbligand=5MU:5-METHYLURIDINE+5-MONOPHOSPHATE'>5MU</scene>, <scene name='pdbligand=6MZ:N6-METHYLADENOSINE-5-MONOPHOSPHATE'>6MZ</scene>, <scene name='pdbligand=7MG:7N-METHYL-8-HYDROGUANOSINE-5-MONOPHOSPHATE'>7MG</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=OMC:O2-METHYLYCYTIDINE-5-MONOPHOSPHATE'>OMC</scene>, <scene name='pdbligand=OMG:O2-METHYLGUANOSINE-5-MONOPHOSPHATE'>OMG</scene>, <scene name='pdbligand=OMU:O2-METHYLURIDINE+5-MONOPHOSPHATE'>OMU</scene>, <scene name='pdbligand=PSU:PSEUDOURIDINE-5-MONOPHOSPHATE'>PSU</scene>, <scene name='pdbligand=UR3:3-METHYLURIDINE-5-MONOPHOSHATE'>UR3</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=6q97 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6q97 OCA], [https://pdbe.org/6q97 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6q97 RCSB], [https://www.ebi.ac.uk/pdbsum/6q97 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6q97 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RL3_ECOLI RL3_ECOLI] One of two assembly inititator proteins, it binds directly near the 3'-end of the 23S rRNA, where it nucleates assembly of the 50S subunit.[HAMAP-Rule:MF_01325_B]
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== Publication Abstract from PubMed ==
During trans-translation, transfer-messenger RNA (tmRNA) and small protein B (SmpB) together rescue ribosomes stalled on a truncated mRNA and tag the nascent polypeptide for degradation. We used cryo-electron microscopy to determine the structures of three key states of the tmRNA-SmpB-ribosome complex during trans translation at resolutions of 3.7 to 4.4 angstroms. The results show how tmRNA and SmpB act specifically on stalled ribosomes and how the circularized complex moves through the ribosome, enabling translation to switch from the old defective message to the reading frame on tmRNA.

How a circularized tmRNA moves through the ribosome.,Rae CD, Gordiyenko Y, Ramakrishnan V Science. 2019 Feb 15;363(6428):740-744. doi: 10.1126/science.aav9370. PMID:30765567<ref>PMID:30765567</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 6q97" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribosome 3D structures|Ribosome 3D structures]]
== References ==
<references/>
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[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Rae CD]]