Open AccessIdentification of an outer membrane protein required for the transport of lipopolysaccharide to the bacterial cell surface
Author(s) -
Martine P. Bos,
Boris Tefsen,
Jeroen Geurtsen,
Jan Tommassen
Publication year - 2004
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0402340101
Subject(s) - bacterial outer membrane , lipopolysaccharide , gram negative bacteria , bacteria , biogenesis , extracellular , membrane permeability , cell membrane , escherichia coli , biology , cell envelope , membrane protein , microbiology and biotechnology , bacterial cell structure , biochemistry , chemistry , neisseria meningitidis , membrane , immunology , genetics , gene
Lipopolysaccharide (LPS), also known as endotoxin due to its severe pathophysiological effects in infected subjects, is an essential component of the outer membrane (OM) of most Gram-negative bacteria. LPS is synthesized in the bacterial inner membrane, a process that is now well understood. In contrast, the mechanism of its transport to the outer leaflet of the OM has remained enigmatic. We demonstrate here that the OM protein, known as increased membrane permeability (Imp) or organic solvent tolerance protein, is involved in this process. An Imp-deficient mutant of Neisseria meningitidis was viable and produced severely reduced amounts of LPS. The limited amount of LPS that was still produced was not accessible to LPS-modifying enzymes expressed in the OM or added to the extracellular medium. We conclude therefore that Imp mediates the transport of LPS to the cell surface. The role of Imp in LPS biogenesis and its high conservation among Gram-negative bacteria make it an excellent target for the development of novel antibacterial compounds.