5ldf

Maltose binding protein genetically fused to dodecameric glutamine synthetaseMaltose binding protein genetically fused to dodecameric glutamine synthetase

5ldf, resolution 6.20Å Show:Asymmetric Unit Biological Assembly Structural highlights 5ldf is a 24 chain structure with sequence from Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhi. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 6.2Å Ligands: Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GLN1B_SALTI Catalyzes the ATP-dependent biosynthesis of glutamine from glutamate and ammonia.[UniProtKB:P0A1P6] Publication Abstract from PubMed Recent technical advances have revolutionized the field of cryo-electron microscopy (cryo-EM). However, most monomeric proteins remain too small (<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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glutamine synthetase 3D structures Maltose-binding protein 3D structures