View source for 9h85


==BAM-hinge (GSGS)==
<StructureSection load='9h85' size='340' side='right'caption='[[9h85]], [[Resolution|resolution]] 4.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9h85]] is a 5 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=9H85 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9H85 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]] 4.2&#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=9h85 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9h85 OCA], [https://pdbe.org/9h85 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9h85 RCSB], [https://www.ebi.ac.uk/pdbsum/9h85 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9h85 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BAMA_ECOLI BAMA_ECOLI] Part of the outer membrane protein assembly complex, which is involved in assembly and insertion of beta-barrel proteins into the outer membrane. Constitutes, with BamD, the core component of the assembly machinery.<ref>PMID:15951436</ref> <ref>PMID:16102012</ref> <ref>PMID:16824102</ref> <ref>PMID:20378773</ref> <ref>PMID:21823654</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The beta-barrel assembly machinery (BAM) inserts beta-barrel proteins into the outer membrane of Gram-negative bacteria, forming an essential permeability barrier. The core BAM component, BamA, is a beta-barrel protein with an N-terminal periplasmic extension comprising five polypeptide transport-associated (POTRA) domains. Whilst BamA's structure is well characterised, it remains unclear how beta-barrel and POTRA domain motions are coordinated. Using BamA variants with mutations in the hinge region between these two domains, we demonstrate that hinge flexibility is required for BAM function. Cryo-electron microscopy suggests that hinge rigidity impairs function by structurally decoupling these domains. A screen for spontaneous suppressors identified a mutation at position T434 in an extracellular loop of BamA, which has been previously shown to suppress BAM defects. Studying this variant provides insights into its function as a general rescue mechanism. Our findings underscore how BamA's sequence has been evolutionarily optimised for efficient function.

Molecular insights into how the motions of the beta-barrel and POTRA domains of BamA are coupled for efficient function.,Csoma N, Machin JM, Whitehouse JM, Rodriguez-Alonso R, Olejnik M, Cahill AK, Cho SH, Schaberle TF, Iorga BI, Ranson NA, Radford SE, Calabrese AN, Collet JF Nat Commun. 2025 Oct 3;16(1):8832. doi: 10.1038/s41467-025-63897-y. PMID:41044071<ref>PMID:41044071</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9h85" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Machin JM]]
[[Category: Ranson NA]]