A dual control mechanism synchronizes riboflavin and sulphur metabolism in Bacillus subtilis.
Flavin mononucleotide (FMN) riboswitches are genetic elements, which in many bacteria control genes responsible for biosynthesis and/or transport of riboflavin (rib genes). Cytoplasmic riboflavin is rapidly and almost completely converted to FMN by flavokinases. When cytoplasmic levels of FMN are sufficient ("high levels"), FMN binding to FMN riboswitches leads to a reduction of rib gene expression. We report here that the protein RibR counteracts the FMN-induced "turn-off" activities of both FMN riboswitches in Bacillus subtilis, allowing rib gene expression even in the presence of high levels of FMN. The reason for this secondary metabolic control by RibR is to couple sulfur metabolism with riboflavin metabolism.
Department of Biotechnology, Institute for Technical Microbiology, Hochschule Mannheim, 68163 Mannheim, Germany; Department of Bioprocess and Biotechnology, School of Pharmaceutical Sciences, Universidade Estadual Paulista (UNESP), 14801-902 Araraquara, Brazil;
Danielle Biscaro
DB
Pedrolli
Department of Biotechnology, Institute for Technical Microbiology, Hochschule Mannheim, 68163 Mannheim, Germany;
Christian
C
Kühm
Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland;
Daniel C
DC
Sévin
Department of Biology, Technical University Darmstadt, 64287 Darmstadt, Germany.
Michael P
MP
Vockenhuber
Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland;
Uwe
U
Sauer
Department of Biology, Technical University Darmstadt, 64287 Darmstadt, Germany.
Beatrix
B
Suess
Department of Biotechnology, Institute for Technical Microbiology, Hochschule Mannheim, 68163 Mannheim, Germany; m.mack@hs-mannheim.de.
Matthias
M
Mack
D001412:Bacillus subtilis / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D005486:Flavin Mononucleotide / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D055442:Metabolome / Q000235:genetics; D011994:Recombinant Proteins / Q000302:isolation & purification; D012256:Riboflavin / Q000378:metabolism*; D058928:Riboswitch / Q000502:physiology*; D013455:Sulfur / Q000378:metabolism*
D011994:Recombinant Proteins; D058928:Riboswitch; D013455:Sulfur; D005486:Flavin Mononucleotide; D012256:Riboflavin
Bacillus subtilis; FMN riboswitch; RibR; flavin mononucleotide; riboflavin