Structural characterization of Escherichia coli BamE, a lipoprotein component of the ß-barrel assembly machinery complex.
Biochemistry
; 50(6): 1081-90, 2011 Feb 15.
Article
em En
| MEDLINE
| ID: mdl-21207987
ABSTRACT
In Escherichia coli, the BAM complex catalyzes the essential process of assembling outer membrane proteins (OMPs). This complex consists of five proteins one membrane-bound protein, BamA, and four lipoproteins, BamB, BamC, BamD, and BamE. Despite their importance in OMP biogenesis, there is currently a lack of functional and structural information on the BAM complex lipoproteins. BamE is the smallest but most conserved lipoprotein in the complex. The structural and dynamic properties of monomeric BamE (residues 21-133) were determined by NMR spectroscopy. The protein folds as two α-helices packed against a three-stranded antiparallel ß-sheet. The N-terminal (Ser21-Thr39) and C-terminal (Pro108-Asn113) residues, as well as a ß-hairpin loop (Val76-Gln89), are highly flexible on the subnanosecond time scale. BamE expressed and purified from E. coli also exists in a kinetically trapped dimeric state that has dramatically different NMR spectra, and hence structural features, relative to its monomeric form. The functional significance of the BamE dimer remains to be established. Structural comparison to proteins with a similar architecture suggests that BamE may play a role in mediating the association of the BAM complex or with the BAM complex substrates.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas da Membrana Bacteriana Externa
/
Proteínas de Escherichia coli
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Escherichia coli
Idioma:
En
Revista:
Biochemistry
Ano de publicação:
2011
Tipo de documento:
Article