Insight into the conformational stability of membrane-embedded BamA using a combined solution and solid-state NMR approach.
 

Insight into the conformational stability of membrane-embedded BamA using a combined solution and solid-state NMR approach.

Related Articles Insight into the conformational stability of membrane-embedded BamA using a combined solution and solid-state NMR approach.

J Biomol NMR. 2015 Jan 8;

Authors: Sinnige T, Houben K, Pritisanac I, Renault M, Boelens R, Baldus M

Abstract
The ?-barrel assembly machinery (BAM) is involved in folding and insertion of outer membrane proteins in Gram-negative bacteria, a process that is still poorly understood. With its 790 residues, BamA presents a challenge to current NMR methods. We utilized a "divide and conquer" approach in which we first obtained resonance assignments for BamA's periplasmic POTRA domains 4 and 5 by solution NMR. Comparison of these assignments to solid-state NMR (ssNMR) data obtained on two BamA constructs including the transmembrane domain and one or two soluble POTRA domains suggested that the fold of POTRA domain 5 critically depends on the interface with POTRA 4. Using specific labeling schemes we furthermore obtained ssNMR resonance assignments for residues in the extracellular loop 6 that is known to be crucial for BamA-mediated substrate folding and insertion. Taken together, our data provide novel insights into the conformational stability of membrane-embedded, non-crystalline BamA.


PMID: 25567766 [PubMed - as supplied by publisher]



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