title: Conformational Plasticity of the POTRA 5 Domain in the Outer Membrane Protein Assembly Factor BamA.
abstract: BamA is the main component of the β-barrel assembly machinery (BAM) that folds and inserts outer membrane proteins in Gram-negative bacteria. Crystal structures have suggested that this process involves conformational changes in the transmembrane β-barrel of BamA that allow for lateral opening, as well as large overall rearrangements of its periplasmic POTRA domains. Here, we identify local dynamics of the BamA POTRA 5 domain by solution and solid-state nuclear magnetic resonance. The protein region undergoing conformational exchange is highly conserved and contains residues critical for interaction with BamD and correct β-barrel assembly in vivo. We show that mutations known to affect the latter processes influence the conformational equilibrium, suggesting that the plasticity of POTRA 5 is related to its interaction with BamD and possibly to substrate binding. Taken together, a view emerges in which local protein plasticity may be critically involved in the different stages of outer membrane protein folding and insertion.
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
authors.forename: Tessa
authors.initials: T
authors.lastname: Sinnige
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
authors.forename: Markus
authors.initials: M
authors.lastname: Weingarth
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
authors.forename: Mark
authors.initials: M
authors.lastname: Daniëls
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
authors.forename: Rolf
authors.initials: R
authors.lastname: Boelens
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
authors.forename: Alexandre M J J
authors.initials: AM
authors.lastname: Bonvin
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands. Electronic address: k.houben@uu.nl.
authors.forename: Klaartje
authors.initials: K
authors.lastname: Houben
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands. Electronic address: m.baldus@uu.nl.
authors.forename: Marc
authors.initials: M
authors.lastname: Baldus
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D001425:Bacterial Outer Membrane Proteins; C503914:BamA protein, E coli; D029968:Escherichia coli Proteins