title: The riboflavin kinase encoding gene ribR of Bacillus subtilis is a part of a 10 kb operon, which is negatively regulated by the yrzC gene product.
abstract: The riboflavin kinase encoding gene ribR is situated within a 12 genes locus ytmI-ytnM of the Bacillus subtilis chromosome. Here we demonstrate that ribR is transcribed as part of a 10 kb ytmI-ytnM operon. The riboflavin overproduction phenotype of B. subtilis ribC mutant strains, which is a result of the strongly reduced flavokinase activity of the riboflavin kinase/FAD synthetase RibC, was suppressed by ribR expression. Analysis of mutations with an upregulated ribR gene revealed 2 different groups of mutants. One class of mutants contained base substitutions in an 8 nucleotide sequence of the promoter region of the ytmI-ytnM operon. A second class of mutants had single point mutations within the yrzC gene or in the RBS of this gene. Dot-blot analysis of ytmI-ytnM transcription and the results of in trans complementation experiments for the yrzC mutants confirmed a role of the yrzC gene product as a negative regulator for the ytmI-ytnM operon.
authors.affiliation: Molecular and Radiation Biophysics Division, St. Petersburg Nuclear Physics Institute of the Russian Academy of Sciences, Gatchina, Leningrad district 188350, Russia. solovieva@em.uni-frankfurt.de
authors.forename: Irina M
authors.initials: IM
authors.lastname: Solovieva
authors.forename: Rimma A
authors.initials: RA
authors.lastname: Kreneva
authors.forename: Lubov
authors.initials: L
authors.lastname: Errais Lopes
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Perumov
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D009876:Operon; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics* / Q000378:metabolism*; D012256:Riboflavin / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); C022532:riboflavin kinase; D012256:Riboflavin