Characterization of a stalled complex on the β-barrel assembly machine.

TitleCharacterization of a stalled complex on the β-barrel assembly machine.
Publication TypeJournal Article
Year of Publication2016
AuthorsLee, J, Xue, M, Wzorek, JS, Wu, T, Grabowicz, M, Gronenberg, LS, Sutterlin, HA, Davis, RM, Ruiz, N, Silhavy, TJ, Kahne, DE
JournalProc Natl Acad Sci U S A
Volume113
Issue31
Pagination8717-22
Date Published2016 Aug 2
ISSN1091-6490
Abstract

<p>The assembly of β-barrel proteins into membranes is mediated by an evolutionarily conserved machine. This process is poorly understood because no stable partially folded barrel substrates have been characterized. Here, we slowed the folding of the Escherichia coli β-barrel protein, LptD, with its lipoprotein plug, LptE. We identified a late-stage intermediate in which LptD is folded around LptE, and both components interact with the two essential β-barrel assembly machine (Bam) components, BamA and BamD. We propose a model in which BamA and BamD act in concert to catalyze folding, with the final step in the process involving closure of the ends of the barrel with release from the Bam components. Because BamD and LptE are both soluble proteins, the simplest model consistent with these findings is that barrel folding by the Bam complex begins in the periplasm at the membrane interface.</p>

DOI10.1073/pnas.1604100113
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID27439868
PubMed Central IDPMC4978274
Grant ListR01 GM100951 / GM / NIGMS NIH HHS / United States
R01 GM034821 / GM / NIGMS NIH HHS / United States
F32 GM108258 / GM / NIGMS NIH HHS / United States
R01 AI081059 / AI / NIAID NIH HHS / United States
R37 GM034821 / GM / NIGMS NIH HHS / United States
F31 GM116210 / GM / NIGMS NIH HHS / United States