title: Cpe1786/IscR of Clostridium perfringens represses expression of genes involved in Fe-S cluster biogenesis.
abstract: Cpe1786 of Clostridium perfringens is an Rrf2-type regulator containing the three-cysteine residues coordinating a Fe-S in IscR, the repressor controlling Fe-S homeostasis in enterobacteria. The cpe1786 gene formed an operon with iscSU involved in Fe-S biogenesis and tmrU. This operon was transcribed from a σA-dependent promoter. We showed that in the heterologous host Bacillus subtilis, Cpe1786, renamed IscRCp, negatively controlled its own transcription. We constructed an iscR mutant in C. perfringens. We then compared the expression profile of strain 13 and of the iscR mutant. IscRCpcontrolled expression of genes involved in Fe-S biogenesis, in amino acid or sugar metabolisms, in fermentation pathways and in host compound utilization. We then demonstrated, using a ChIP-PCR experiment, that IscRCpinteracted with its promoter region in vivo in C. perfringens and with the promoter of cpe2093 encoding an amino acid ABC transporter. We utilized a comparative genomic approach to infer a candidate IscR binding motif and reconstruct IscR regulons in clostridia. We showed that point mutations in the conserved motif of 29 bp identified upstream of iscR decreased the cysteine-dependent repression of iscR mediated by IscRCp.
authors.affiliation: Institut Pasteur, Laboratoire de Pathogénèse des Bactéries anaérobies, 28 rue du Docteur Roux, 75015 Paris, France; Université Paris 7-Denis Diderot, Sorbonne Paris Cité, 75205 Paris, France.
authors.forename: Gaelle
authors.initials: G
authors.lastname: André
authors.affiliation: Institut Pasteur, Laboratoire de Pathogénèse des Bactéries anaérobies, 28 rue du Docteur Roux, 75015 Paris, France; Université Paris 7-Denis Diderot, Sorbonne Paris Cité, 75205 Paris, France.
authors.forename: Elise
authors.initials: E
authors.lastname: Haudecoeur
authors.affiliation: Institut Pasteur, Laboratoire de Pathogénèse des Bactéries anaérobies, 28 rue du Docteur Roux, 75015 Paris, France; Université Paris 7-Denis Diderot, Sorbonne Paris Cité, 75205 Paris, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Courtois
authors.affiliation: Institut Pasteur, Laboratoire de Pathogénèse des Bactéries anaérobies, 28 rue du Docteur Roux, 75015 Paris, France; Université Paris 7-Denis Diderot, Sorbonne Paris Cité, 75205 Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Monot
authors.affiliation: Institut Pasteur, Laboratoire de Pathogénèse des Bactéries anaérobies, 28 rue du Docteur Roux, 75015 Paris, France; Université Paris 7-Denis Diderot, Sorbonne Paris Cité, 75205 Paris, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Dupuy
authors.affiliation: Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127994, Russia.
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Rodionov
authors.affiliation: Institut Pasteur, Laboratoire de Pathogénèse des Bactéries anaérobies, 28 rue du Docteur Roux, 75015 Paris, France; Université Paris 7-Denis Diderot, Sorbonne Paris Cité, 75205 Paris, France. Electronic address: isabelle.martin-verstraete@pasteur.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Martin-Verstraete
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D020816:Amino Acid Motifs / Q000235:genetics; D001665:Binding Sites / Q000235:genetics; D003016:Clostridium perfringens / Q000235:genetics* / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005809:Genes, Regulator / Q000235:genetics*; D007506:Iron-Sulfur Proteins / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics
chemical_list: D018528:ATP-Binding Cassette Transporters; D005232:Fatty Acids, Volatile; D007506:Iron-Sulfur Proteins; D012097:Repressor Proteins
keywords: Clostridia; Cysteine-dependent regulation; Fermentation; Fe–S clusters; Rrf2 repressor