title: Fur is involved in manganese-dependent regulation of mntA (sitA) expression in Sinorhizobium meliloti.
abstract: Fur is a transcriptional regulator involved in iron-dependent control of gene expression in many bacteria. In this work we analyzed the phenotype of a fur mutant in Sinorhizobium meliloti, an alpha-proteobacterium that fixes N(2) in association with host plants. We demonstrated that some functions involved in high-affinity iron transport, siderophore production, and iron-regulated outer membrane protein expression respond to iron in a Fur-independent manner. However, manganese-dependent expression of the MntABCD manganese transport system was lost in a fur strain as discerned by constitutive expression of a mntA::gfp fusion reporter gene in the mutant. Thus, Fur directly or indirectly regulates a manganese-dependent function. The data indicate a novel function for a bacterial Fur protein in mediating manganese-dependent regulation of gene expression.
authors.affiliation: Laboratorio de Ecología Microbiana, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Unidad Asociada a la Facultad de Ciencias, Montevideo 11600, Uruguay.
authors.forename: Raúl
authors.initials: R
authors.lastname: Platero
authors.forename: Lucía
authors.initials: L
authors.lastname: Peixoto
authors.forename: Mark R
authors.initials: MR
authors.lastname: O'Brian
authors.forename: Elena
authors.initials: E
authors.lastname: Fabiano
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D008345:Manganese / Q000378:metabolism*; D009876:Operon; D012097:Repressor Proteins / Q000502:physiology*; D017262:Siderophores / Q000096:biosynthesis; D016962:Sinorhizobium meliloti / Q000235:genetics*; D013559:Symbiosis
chemical_list: D018528:ATP-Binding Cassette Transporters; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D012097:Repressor Proteins; D017262:Siderophores; C068477:ferric uptake regulating proteins, bacterial; D008345:Manganese; D007501:Iron