Mass spectrometry defines the C-terminal dimerization domain and enables modeling of the structure of full-length OmpA

TY - JOUR

T1 - Mass spectrometry defines the C-terminal dimerization domain and enables modeling of the structure of full-length OmpA

AU - Marcoux, Julien

AU - Politis, Anargyros

AU - Rinehart, Dennis

AU - Marshall, David P.

AU - Wallace, Mark I.

AU - Tamm, Lukas K.

AU - Robinson, Carol V.

N1 - © 2014 Elsevier Ltd.

PY - 2014/5/6

Y1 - 2014/5/6

N2 - The transmembrane domain of the outer membrane protein A (OmpA) from Escherichia coli is an excellent model for structural and folding studies of β-barrel membrane proteins. However, full-length OmpA resists crystallographic efforts, and the link between its function and tertiary structure remains controversial. Here we use site-directed mutagenesis and mass spectrometry of different constructs of OmpA, released in the gas phase from detergent micelles, to define the minimal region encompassing the C-terminal dimer interface. Combining knowledge of the location of the dimeric interface with molecular modeling and ion mobility data allows us to propose a low-resolution model for the full-length OmpA dimer. Our model of the dimer is in remarkable agreement with experimental ion mobility data, with none of the unfolding or collapse observed for full-length monomeric OmpA, implying that dimer formation stabilizes the overall structure and prevents collapse of the flexible linker that connects the two domains. 

AB - The transmembrane domain of the outer membrane protein A (OmpA) from Escherichia coli is an excellent model for structural and folding studies of β-barrel membrane proteins. However, full-length OmpA resists crystallographic efforts, and the link between its function and tertiary structure remains controversial. Here we use site-directed mutagenesis and mass spectrometry of different constructs of OmpA, released in the gas phase from detergent micelles, to define the minimal region encompassing the C-terminal dimer interface. Combining knowledge of the location of the dimeric interface with molecular modeling and ion mobility data allows us to propose a low-resolution model for the full-length OmpA dimer. Our model of the dimer is in remarkable agreement with experimental ion mobility data, with none of the unfolding or collapse observed for full-length monomeric OmpA, implying that dimer formation stabilizes the overall structure and prevents collapse of the flexible linker that connects the two domains. 

UR - http://www.scopus.com/inward/record.url?scp=84899817875&partnerID=8YFLogxK

U2 - 10.1016/j.str.2014.03.004

DO - 10.1016/j.str.2014.03.004

M3 - Article

AN - SCOPUS:84899817875

SN - 0969-2126

VL - 22

SP - 781

EP - 790

JO - Structure

JF - Structure

IS - 5

ER -