View source for 9psi


==In situ structure of the human mitoribosome in the A-P-E state from TACO1-knockout cells==
<StructureSection load='9psi' size='340' side='right'caption='[[9psi]], [[Resolution|resolution]] 3.12&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9psi]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9PSI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9PSI 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]] 3.12&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1MA:6-HYDRO-1-METHYLADENOSINE-5-MONOPHOSPHATE'>1MA</scene>, <scene name='pdbligand=2MG:2N-METHYLGUANOSINE-5-MONOPHOSPHATE'>2MG</scene>, <scene name='pdbligand=5MC:5-METHYLCYTIDINE-5-MONOPHOSPHATE'>5MC</scene>, <scene name='pdbligand=5MU:5-METHYLURIDINE+5-MONOPHOSPHATE'>5MU</scene>, <scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=ATP:ADENOSINE-5-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=B8T:[(2~{R},3~{S},4~{R},5~{R})-5-[4-(methylamino)-2-oxidanylidene-pyrimidin-1-yl]-3,4-bis(oxidanyl)oxolan-2-yl]methyl+dihydrogen+phosphate'>B8T</scene>, <scene name='pdbligand=FES:FE2/S2+(INORGANIC)+CLUSTER'>FES</scene>, <scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MA6:6N-DIMETHYLADENOSINE-5-MONOPHOSHATE'>MA6</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</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=PUT:1,4-DIAMINOBUTANE'>PUT</scene>, <scene name='pdbligand=SPD:SPERMIDINE'>SPD</scene>, <scene name='pdbligand=SPM:SPERMINE'>SPM</scene>, <scene name='pdbligand=VAL:VALINE'>VAL</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=9psi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9psi OCA], [https://pdbe.org/9psi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9psi RCSB], [https://www.ebi.ac.uk/pdbsum/9psi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9psi ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Translation elongation is a universally conserved step in protein synthesis, relying on elongation factors that engage the ribosomal L7/L12 stalk to mediate aminoacyl-tRNA delivery, accommodation, and ribosomal translocation. Using in organello cryo-electron microscopy, we reveal how the mitochondrial translation accelerator TACO1 promotes efficient elongation on human mitoribosomes. TACO1 binds the mitoribosomal region typically bound by elongation factor Tu (mtEF-Tu), bridging the large and small subunits via contacts with 16S rRNA, bL12m, A-site tRNA, and uS12m. While active throughout elongation, TACO1 is especially critical when translating polyproline motifs. Its absence prolongs mtEF-Tu residence in A/T states, causes persistent mitoribosomal stalling and premature subunit dissociation. Structural analyses indicate that TACO1 competes with mtEF-Tu for mitoribosome binding, stabilizes A-site tRNA, and enhances peptidyl transfer through a mechanism distinct from EF-P and eIF5A. These findings suggest that bacterial TACO1 orthologs may serve analogous roles, highlighting an evolutionarily conserved strategy for maintaining elongation efficiency during challenging translation events.

Structural basis of TACO1-mediated efficient mitochondrial translation.,Wang S, Brischigliaro M, Zhang Y, Wu C, Zheng W, Barrientos A, Xiong Y Nat Commun. 2026 Feb 9. doi: 10.1038/s41467-026-69156-y. PMID:41663403<ref>PMID:41663403</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9psi" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Wang S]]
[[Category: Xiong Y]]
[[Category: Zhang Y]]