Biochemical characterization of an ABC transporter LptBFGC complex required for the outer membrane sorting of lipopolysaccharides

Abstract 

Seven Lpt proteins (A through G) are thought to be involved in lipopolysaccharide transport from the inner to outer membrane of Escherichia coli. LptB belongs to the ATP-binding cassette transporter superfamily. Although the lptB gene lacks neighboring genes encoding membrane subunits, bioinformatic analyses recently indicated that two distantly located consecutive genes, lptF and lptG, could encode membrane subunits. To examine this possibility, LptB was expressed with LptF and LptG. We report here that both LptF and LptG formed a complex with LptB. Furthermore, an inner membrane protein, LptC, which had been implicated in lipopolysaccharide transport, was also included in this complex.

Structured summary

MINT-7137021: lptb (uniprotkb:P0A9V1) physically interacts (MI:0914) with lptc (uniprotkb:P0ADV9), lptg (uniprotkb:P0ADC6) and lptf (uniprotkb:P0AF98) by pull down (MI:0096)

MINT-7137160: lptb (uniprotkb:P0A9V1) physically interacts (MI:0914) with lptf (uniprotkb:P0AF98) and lptg (uniprotkb:P0ADC6) by pull down (MI:0096)

Abbreviations: ABC, ATP-binding cassette, CBB, Coomassie Brilliant Blue R-250, DDM, n-dodecyl-β-d-maltopyranoside, IMAC, immobilized metal affinity chromatography, IPTG, isopropyl-1-thio-β-d-galactopyranoside, LPS, lipopolysaccharides

Keywords: ABC transporter, Lipopolysaccharide, Lipid A, ATP hydrolysis