View source for 5ldf


==Maltose binding protein genetically fused to dodecameric glutamine synthetase==
<SX load='5ldf' size='340' side='right' viewer='molstar' caption='[[5ldf]], [[Resolution|resolution]] 6.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ldf]] is a 24 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_O157:H7 Escherichia coli O157:H7] and [https://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_Typhi Salmonella enterica subsp. enterica serovar Typhi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5LDF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5LDF 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]] 6.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PRD_900001:alpha-maltose'>PRD_900001</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=5ldf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ldf OCA], [https://pdbe.org/5ldf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ldf RCSB], [https://www.ebi.ac.uk/pdbsum/5ldf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ldf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GLN1B_SALTI GLN1B_SALTI] Catalyzes the ATP-dependent biosynthesis of glutamine from glutamate and ammonia.[UniProtKB:P0A1P6]
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== Publication Abstract from PubMed ==
Recent technical advances have revolutionized the field of cryo-electron microscopy (cryo-EM). However, most monomeric proteins remain too small (&lt;100 kDa) for cryo-EM analysis. To overcome this limitation, we explored a strategy whereby a monomeric target protein is genetically fused to a homo-oligomeric scaffold protein and the junction optimized to allow the target to adopt the scaffold symmetry, thereby generating a chimeric particle suitable for cryo-EM. To demonstrate the concept, we fused maltose-binding protein (MBP), a 40 kDa monomer, to glutamine synthetase, a dodecamer formed by two hexameric rings. Chimeric constructs with different junction lengths were screened by biophysical analysis and negative-stain EM. The optimal construct yielded a cryo-EM reconstruction that revealed the MBP structure at sub-nanometre resolution. These findings illustrate the feasibility of using homo-oligomeric scaffolds to enable cryo-EM analysis of monomeric proteins, paving the way for applying this strategy to challenging structures resistant to crystallographic and NMR analysis.

Fusion to a homo-oligomeric scaffold allows cryo-EM analysis of a small protein.,Coscia F, Estrozi LF, Hans F, Malet H, Noirclerc-Savoye M, Schoehn G, Petosa C Sci Rep. 2016 Aug 3;6:30909. doi: 10.1038/srep30909. PMID:27485862<ref>PMID:27485862</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 5ldf" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glutamine synthetase 3D structures|Glutamine synthetase 3D structures]]
*[[Maltose-binding protein 3D structures|Maltose-binding protein 3D structures]]
== References ==
<references/>
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</SX>
[[Category: Escherichia coli O157:H7]]
[[Category: Large Structures]]
[[Category: Salmonella enterica subsp. enterica serovar Typhi]]
[[Category: Coscia F]]
[[Category: Petosa C]]
[[Category: Schoehn G]]