Regulation of riboflavin biosynthesis and transport genes in bacteria by transcriptional and translational attenuation.
The riboflavin biosynthesis in bacteria was analyzed using comparative analysis of genes, operons and regulatory elements. A model for regulation based on formation of alternative RNA structures involving the RFN elements is suggested. In Gram-positive bacteria including actinomycetes, Thermotoga, Thermus and Deinococcus, the riboflavin metabolism and transport genes are predicted to be regulated by transcriptional attenuation, whereas in most Gram-negative bacteria, the riboflavin biosynthesis genes seem to be regulated on the level of translation initiation. Several new candidate riboflavin transporters were identified (impX in Desulfitobacterium halfniense and Fusobacterium nucleatum; pnuX in several actinomycetes, including some Corynebacterium species and Strepto myces coelicolor; rfnT in Rhizobiaceae). Traces of a number of likely horizontal transfer events were found: the complete riboflavin operon with the upstream regulatory element was transferred to Haemophilus influenzae and Actinobacillus pleuropneumoniae from some Gram-positive bacterium; non-regulated riboflavin operon in Pyrococcus furiousus was likely transferred from Thermotoga; and the RFN element was inserted into the riboflavin operon of Pseudomonas aeruginosa from some other Pseudomonas species, where it had regulated the ribH2 gene.
Vitreschak
Alexey G
AG
Institute for Problems of Information Transmission, Moscow, 101447, Russia.
Rodionov
Dmitry A
DA
Mironov
Andrey A
AA
Gelfand
Mikhail S
MS
D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D009690:Nucleic Acid Conformation; D009876:Operon / Q000235:genetics; D010802:Phylogeny; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012256:Riboflavin / Q000096:biosynthesis* / Q000378:metabolism; D012258:Riboflavin Synthase / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D009097:Multienzyme Complexes; D012329:RNA, Bacterial; C044822:6,7-dimethyl-8-ribityllumazine synthase; D012258:Riboflavin Synthase; D012256:Riboflavin