title: Association of iron-regulated outer membrane proteins of Neisseria meningitidis with the RmpM (class 4) protein.
abstract: The RmpM (class 4) protein of Neisseria meningitidis has previously been shown to be associated with the outer membrane porins. In the present study, we demonstrate that this protein forms complexes with the lactoferrin receptor LbpA, the transferrin receptor TbpA and the siderophore receptor FrpB as well. This complexation apparently resulted in a stabilization of oligomeric forms of these iron-regulated proteins. In vitro experiments further revealed a reduced ability to acquire iron from human lactoferrin in the rmpM mutant. Furthermore, all TonB-dependent receptors investigated here appeared to exist as oligomers (probably dimers), suggesting that this is a general feature of this class of proteins.
authors.affiliation: Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands. t.c.prinz@bio.uu.nl
authors.forename: T
authors.initials: T
authors.lastname: Prinz
authors.forename: J
authors.initials: J
authors.lastname: Tommassen
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007501:Iron / Q000378:metabolism*; D033862:Iron-Binding Proteins; D008970:Molecular Weight; D009345:Neisseria meningitidis / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D033863:Transferrin-Binding Proteins
chemical_list: D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C093120:FrpB protein, bacteria; D033862:Iron-Binding Proteins; C112566:LBPA protein, Neisseria meningitidis; D011956:Receptors, Cell Surface; C051591:Rmp protein, Neisseria; D033863:Transferrin-Binding Proteins; D007501:Iron