title: SufS is a NifS-like protein, and SufD is necessary for stability of the [2Fe-2S] FhuF protein in Escherichia coli.
abstract: Escherichia coli fhuF mutants, a sufS::MudI mutant, and a sufD::MudI mutant were found to have the same phenotype: the inability to use ferrioxamine B as an iron source in a plate assay. In addition, the sufS and sufD genes were shown to be regulated by the iron-dependent Fur repressor. Sequence analysis revealed that the sufS open reading frame corresponds to orf f406. The protein SufS belongs to the family of NifS-like proteins, which supply sulfur for [Fe-S] centers. The protein FhuF contains a [2Fe-2S] center. A mutation in the upstream sufD gene (orf f423) caused the same phenotype. The T7 expression system and a His tag allow the isolation in good yield of the FhuF protein from a wild-type strain. In contrast, overproduction of the protein in a DeltasufD strain failed. Radioactive labeling of N-His-FhuF with [35S]methionine showed that the protein was unstable in the DeltasufD mutant.
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D003676:Deferoxamine / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D005290:Ferric Compounds / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D017930:Genes, Reporter / Q000235:genetics; D007501:Iron / Q000494:pharmacology; D033862:Iron-Binding Proteins; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D016366:Open Reading Frames / Q000235:genetics; D009876:Operon / Q000235:genetics; D033902:Periplasmic Binding Proteins; D020161:Physical Chromosome Mapping; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013696:Temperature