The lipopolysaccharide transport system of Gram-negative bacteria

Sperandeo, Paola; Dehò, Gianni; Polissi, Alessandra

doi:10.1016/j.bbalip.2009.01.011

Cited by 137 publications

(134 citation statements)

References 68 publications

Supporting

Mentioning

131

Contrasting

Unclassified

Order By: Relevance

“…LptD is essential in E. coli (23), and it forms a heterodimer complex with the OM lipoprotein LptE (formerly RlpB) (24,25). The LptD/E complex is the OM component of the Lpt (LPS transport) pathway, which transports LPS from the IM to the outer leaflet of the OM (26,27). Proper assembly of LPS at the cell surface (28) is crucial for the OM to function as a permeability barrier that protects bacteria from hydrophobic antibiotics and detergents (29).…”

mentioning

confidence: 99%

Nonconsecutive disulfide bond formation in an essential integral outer membrane protein

Ruiz

Chng

Hiniker

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

100

174

View full text Add to dashboard Cite

The Gram-negative bacterial envelope is bounded by two membranes. Disulfide bond formation and isomerization in this oxidizing environment are catalyzed by DsbA and DsbC, respectively. It remains unknown when and how the Dsb proteins participate in the biogenesis of outer membrane proteins, which are transported across the cell envelope after their synthesis. The Escherichia coli protein LptD is an integral outer membrane protein that forms an essential complex with the lipoprotein LptE. We show that oxidation of LptD is not required for the formation of the LptD/E complex but it is essential for function. Remarkably, none of the cysteines in LptD are essential because either of two nonconsecutive disulfide bonds suffices for function. Oxidation of LptD, which is efficiently catalyzed by DsbA, does not involve the isomerase DsbC, but it requires LptE. Thus, oxidation is completed only after LptD interacts with LptE, an interaction that occurs at the outer membrane and seems necessary for LptD folding.β-barrel protein | lipoprotein | protein folding

show abstract

mentioning

confidence: 99%

Nonconsecutive disulfide bond formation in an essential integral outer membrane protein

Ruiz

Chng

Hiniker

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

100

174

View full text Add to dashboard Cite

show abstract

“…The LPS biosynthetic pathway has been well characterized (5); however, it is not clear how the cell transports this large amphiphilic molecule across the aqueous periplasmic compartment and to its final location at the cell surface. This process requires seven essential Lpt (lipopolysaccharide transport) proteins that form a transenvelope complex (6,7). Two of these proteins, LptD and LptE (formerly Imp and RlpB, resp.…”

mentioning

confidence: 99%

The complex that inserts lipopolysaccharide into the bacterial outer membrane forms a two-protein plug-and-barrel

Freinkman

Chng

Kahne

2011

Proc. Natl. Acad. Sci. U.S.A.

159

181

View full text Add to dashboard Cite

The cell surfaces of Gram-negative bacteria are composed of lipopolysaccharide (LPS). This glycolipid is found exclusively in the outer leaflet of the asymmetric outer membrane (OM), where it forms a barrier to the entry of toxic hydrophobic molecules into the cell. LPS typically contains six fatty acyl chains and up to several hundred sugar residues. It is biosynthesized in the cytosol and must then be transported across two membranes and an aqueous intermembrane space to the cell surface. These processes are required for the viability of most Gram-negative organisms. The integral membrane β-barrel LptD and the lipoprotein LptE form an essential complex in the OM, which is necessary for LPS assembly. It is not known how this complex translocates large, amphipathic LPS molecules across the OM to the outer leaflet. Here, we show that LptE resides within the LptD β-barrel both in vitro and in vivo. LptD/E associate via an extensive interface; in one specific interaction, LptE contacts a predicted extracellular loop of LptD through the lumen of the β-barrel. Disrupting this interaction site compromises the biogenesis of LptD. This unprecedented two-protein plug-and-barrel architecture suggests how LptD/E can insert LPS from the periplasm directly into the outer leaflet of the OM to establish the asymmetry of the bilayer.lipopolysaccharide assembly | outer membrane protein complex

show abstract

“…Finally, the Oag chains are transferred to the core-lipid A by the ligase WaaL. The Lpt proteins (Lpt A-G) facilitate transport of the LPS from the IM to the OM (Ruiz et al, 2008;Sperandeo et al, 2009). …”

Section: Introductionmentioning

confidence: 99%

“…Oag is composed of oligosaccharide repeat units (RUs) or O units. Oag is linked to the hydrophobic anchor of the LPS (lipid A) by the non-repeating oligosaccharide domain known as the core sugar region (Raetz & Whitfield, 2002;Sperandeo et al, 2009). The complete LPS structure with Oag chains is termed smooth LPS (S-LPS).…”

Section: Introductionmentioning

confidence: 99%

Mutational analysis of the major periplasmic loops of Shigella flexneri Wzy: identification of the residues affecting O antigen modal chain length control, and Wzz-dependent polymerization activity

Nath

Morona

2015

Microbiology

View full text Add to dashboard Cite

The lipopolysaccharide transport system of Gram-negative bacteria

Cited by 137 publications

References 68 publications

Nonconsecutive disulfide bond formation in an essential integral outer membrane protein

Nonconsecutive disulfide bond formation in an essential integral outer membrane protein

The complex that inserts lipopolysaccharide into the bacterial outer membrane forms a two-protein plug-and-barrel

Mutational analysis of the major periplasmic loops of Shigella flexneri Wzy: identification of the residues affecting O antigen modal chain length control, and Wzz-dependent polymerization activity

Contact Info

Product

Resources

About