title: MsbA is not required for phospholipid transport in Neisseria meningitidis.
abstract: The outer membrane of Gram-negative bacteria contains phospholipids and lipopolysaccharide (LPS) in the inner and outer leaflet, respectively. Little is known about the transport of the phospholipids from their site of synthesis to the outer membrane. The inner membrane protein MsbA of Escherichia coli, which is involved in the transport of LPS across the inner membrane, has been reported to be involved in phospholipid transport as well. Here, we have reported the construction and the characterization of a Neisseria meningitidis msbA mutant. The mutant was viable, and it showed a retarded growth phenotype and contained very low amounts of LPS. However, it produced an outer membrane, demonstrating that phospholipid transport was not affected by the mutation. Notably, higher amounts of phospholipids were produced in the msbA mutant than in its isogenic parental strain, provided that capsular biosynthesis was also disrupted. Although these results confirmed that MsbA functions in LPS transport, they also demonstrated that it is not required for phospholipid transport, at least not in N. meningitidis.
authors.affiliation: Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University, 3584 CH Utrecht, The Netherlands.
authors.forename: Boris
authors.initials: B
authors.lastname: Tefsen
authors.forename: Martine P
authors.initials: MP
authors.lastname: Bos
authors.forename: Frank
authors.initials: F
authors.lastname: Beckers
authors.forename: Jan
authors.initials: J
authors.lastname: Tommassen
authors.forename: Hans
authors.initials: H
authors.lastname: de Cock
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism / Q000502:physiology*; D000483:Alleles; D000942:Antigens, Bacterial / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D005816:Genetic Complementation Test; D007612:Kanamycin / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000378:metabolism; D008957:Models, Genetic; D009154:Mutation; D009345:Neisseria meningitidis / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D008070:Lipopolysaccharides; C079726:MsbA protein, Bacteria; D010743:Phospholipids; D007612:Kanamycin