title: A small RNA promotes siderophore production through transcriptional and metabolic remodeling.
abstract: Siderophores are essential factors for iron (Fe) acquisition in bacteria during colonization and infection of eukaryotic hosts, which restrain iron access through iron-binding protein, such as lactoferrin and transferrin. The synthesis of siderophores by Escherichia coli is considered to be fully regulated at the transcriptional level by the Fe-responsive transcriptional repressor Fur. Here we characterized two different pathways that promote the production of the siderophore enterobactin via the action of the small RNA RyhB. First, RyhB is required for normal expression of an important enterobactin biosynthesis polycistron, entCEBAH. Second, RyhB directly represses the translation of cysE, which encodes a serine acetyltransferase that uses serine as a substrate for cysteine biosynthesis. Reduction of CysE activity by RyhB allows serine to be used as building blocks for enterobactin synthesis through the nonribosomal peptide synthesis pathway. Thus, RyhB plays an essential role in siderophore production and may modulate bacterial virulence through optimization of siderophore production.
authors.affiliation: Department of Biochemistry, University of Sherbrooke, Sherbrooke, Quebec, QC, Canada.
authors.forename: Hubert
authors.initials: H
authors.lastname: Salvail
authors.forename: Pascale
authors.initials: P
authors.lastname: Lanthier-Bourbonnais
authors.forename: Jason Michael
authors.initials: JM
authors.lastname: Sobota
authors.forename: Mélissa
authors.initials: M
authors.lastname: Caza
authors.forename: Julie-Anna M
authors.initials: JA
authors.lastname: Benjamin
authors.forename: Martha Eugènia Sequeira
authors.initials: ME
authors.lastname: Mendieta
authors.forename: François
authors.initials: F
authors.lastname: Lépine
authors.forename: Charles M
authors.initials: CM
authors.lastname: Dozois
authors.forename: James
authors.initials: J
authors.lastname: Imlay
authors.forename: Eric
authors.initials: E
authors.lastname: Massé
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004758:Enterobactin / Q000096:biosynthesis* / Q000235:genetics*; D048168:Escherichia coli K12 / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D007501:Iron / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012329:RNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051050:Serine O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D017262:Siderophores / Q000096:biosynthesis* / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D017262:Siderophores; D004758:Enterobactin; D007501:Iron; C070785:CysE protein, E coli; D051050:Serine O-Acetyltransferase