Publications

• Studies on the nature of the enzymic conversion of 6,7-dimethyl-8-ribityllumazine to riboflavin.

  PLAUT G.W.

  J Biol Chem 238:2225-2243(1963) [PubMed] [EuropePMC]

• Riboflavin synthases of Bacillus subtilis. Purification and properties.

  Bacher A., Baur R., Eggers U., Harders H.D., Otto M.K., Schnepple H.

  A variety of Bacillus and Clostridium strains were found to contain two forms of riboflavin synthase which can be easily separated by density gradient centrifugation. The fast sedimenting species accounts for 12 to 44% of the total riboflavin synthase activity in the strains analyzed. Both ribofla ... >> More

  A variety of Bacillus and Clostridium strains were found to contain two forms of riboflavin synthase which can be easily separated by density gradient centrifugation. The fast sedimenting species accounts for 12 to 44% of the total riboflavin synthase activity in the strains analyzed. Both riboflavin synthases were purified to apparent homogeneity from cell extracts of a genetically derepressed mutant of Bacillus subtilis. The specific activities of the pure proteins were 50,000 nmol mg-1 h-1 (light enzyme) and 2,000 nmol mg-1 h-1 (heavy enzyme). The sedimentation velocities (S20,w) were 4.1 and 26.5 S, respectively. Light riboflavin synthase showed a molecular weight of 70,000 in sedimentation equilibrium experiments. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed a single band corresponding to a molecular weight of about 23,500. Thus the enzyme appears to consist of three identical subunits (alpha type). Heavy riboflavin synthase has a molecular weight of 1,000,000 as shown by sedimentation equilibrium analysis. The protein appears to consist of 2 or 3 alpha subunits and approximately 60 beta subunits. A fragment apparently identical with light riboflavin synthase can be obtained from the heavy enzyme by mild dissociating treatment. << Less

  J. Biol. Chem. 255:632-637(1980) [PubMed] [EuropePMC]

• Riboflavin synthesis genes are linked with the lux operon of Photobacterium phosphoreum.

  Lee C.Y., O'Kane D.J., Meighen E.A.

  Four genes immediately downstream of luxG in the Photobacterium phosphoreum lux operon (ribEBHA) have been sequenced and shown to be involved in riboflavin synthesis. Sequence analyses and complementation of Escherichia coli riboflavin auxotrophs showed that the gene products of ribB and ribA are ... >> More

  Four genes immediately downstream of luxG in the Photobacterium phosphoreum lux operon (ribEBHA) have been sequenced and shown to be involved in riboflavin synthesis. Sequence analyses and complementation of Escherichia coli riboflavin auxotrophs showed that the gene products of ribB and ribA are 3,4-dihydroxy-2-butanone 4-phosphate (DHBP) synthetase and GTP cyclohydrolase II, respectively. By expression of P. phosphoreum ribE in E. coli using the bacteriophage T7 promoter-RNA polymerase system, ribE was shown to code for riboflavin synthetase, which catalyzes the conversion of lumazine to riboflavin. Increased thermal stability of RibE on expression with RibH indicated that ribH coded for lumazine synthetase. The organization of the rib genes in P. phosphoreum is quite distinct, with ribB and ribA being linked but separated by ribH, whereas in E. coli, they are unlinked and in Bacillus subtilis, RibB and RibA functions are coded by a single gene. << Less

  J. Bacteriol. 176:2100-2104(1994) [PubMed] [EuropePMC]

• Crystallographic and kinetic study of riboflavin synthase from Brucella abortus, a chemotherapeutic target with an enhanced intrinsic flexibility.

  Serer M.I., Bonomi H.R., Guimaraes B.G., Rossi R.C., Goldbaum F.A., Klinke S.

  Riboflavin synthase (RS) catalyzes the last step of riboflavin biosynthesis in microorganisms and plants, which corresponds to the dismutation of two molecules of 6,7-dimethyl-8-ribityllumazine to yield one molecule of riboflavin and one molecule of 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedion ... >> More

  Riboflavin synthase (RS) catalyzes the last step of riboflavin biosynthesis in microorganisms and plants, which corresponds to the dismutation of two molecules of 6,7-dimethyl-8-ribityllumazine to yield one molecule of riboflavin and one molecule of 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione. Owing to the absence of this enzyme in animals and the fact that most pathogenic bacteria show a strict dependence on riboflavin biosynthesis, RS has been proposed as a potential target for antimicrobial drug development. Eubacterial, fungal and plant RSs assemble as homotrimers lacking C3 symmetry. Each monomer can bind two substrate molecules, yet there is only one active site for the whole enzyme, which is located at the interface between two neighbouring chains. This work reports the crystallographic structure of RS from the pathogenic bacterium Brucella abortus (the aetiological agent of the disease brucellosis) in its apo form, in complex with riboflavin and in complex with two different product analogues, being the first time that the structure of an intact RS trimer with bound ligands has been solved. These crystal models support the hypothesis of enhanced flexibility in the particle and also highlight the role of the ligands in assembling the unique active site. Kinetic and binding studies were also performed to complement these findings. The structural and biochemical information generated may be useful for the rational design of novel RS inhibitors with antimicrobial activity. << Less

  Acta Crystallogr. D 70:1419-1434(2014) [PubMed] [EuropePMC]

• 4-(1'-D-RIBITYLAMINO)-5-AMINO-2,6-DIHYDROXYPYRIMIDINE, THE SECOND PRODUCT OF THE RIBOFLAVIN SYNTHETASE REACTION.

  WACKER H., HARVEY R.A., WINESTOCK C.H., PLAUT G.W.

  J Biol Chem 239:3493-3497(1964) [PubMed] [EuropePMC]