Studies on the biosynthesis of riboflavin. 7. The incorporation of adenine and guanine into riboflavin and into nucleic acid purines in <i>Eremothecium ashbyii</i> and <i>Candida flareri</i>

Audley, B. G.; Goodwin, T. W.

doi:10.1042/bj0840587

Cited by 24 publications

(13 citation statements)

References 16 publications

(6 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The addition of these drugs and another inhibitor of protein synthesis, cycloheximide to the non-growing cell medium brought about little effects on flavinogenesis and only cycloheximide showed a 25% inhibition of riboflavin production at 7mM. 4. It was elucidated from above results that non-growing cell under such the special conditions shows little or no synthesis of protein and purine derivatives but there occurs flavinogenesis to a fair extent.…”

mentioning

confidence: 83%

Development of Specific Experimental Systems for Flavinogenesis Using Non-Growing Cell of Eremothecium ashbyii

Mitsuda

Nakajima

1972

J. Vitaminol

View full text Add to dashboard Cite

Experimental systems using non-growing cell of Eremothecium ashbyii to elucidate the mechanism of flavinogenesis were established in this paper.1. It was found that vacuum infiltration of purines for 2, 3 and 5min and moderate shaking of non-growing cell brought about a good reproducibility of the stimulatory effects on flavinogenesis by purines and furthermore, a higher flavinogenesis.2. The addition of an inhibitor of protein synthesis, chloramphenicol, to the basal medium at the concentration of 6mM after 1day of cultivation resulted in a 45.1% inhibition of the growth measured after 2days of cultivation and a 65.1% inhibition of riboflavin production measured after 4 days of cultivation. On the other hand, the addition of an inhibitor of purine de novo synthesis, sulfanilamide at 4mM resulted in a 24.3% inhibition of the growth after 2 days and a 44.1% inhibition of riboflavin formation after 4days respectively.3. The addition of these drugs and another inhibitor of protein synthesis, cycloheximide to the non-growing cell medium brought about little effects on flavinogenesis and only cycloheximide showed a 25% inhibition of riboflavin production at 7mM.4. It was elucidated from above results that non-growing cell under such the special conditions shows little or no synthesis of protein and purine derivatives but there occurs flavinogenesis to a fair extent.5. It was found that xanthine is the most flavinogenic purine among various purines during these experiments.

show abstract

mentioning

confidence: 83%

Development of Specific Experimental Systems for Flavinogenesis Using Non-Growing Cell of Eremothecium ashbyii

Mitsuda

Nakajima

1972

J. Vitaminol

View full text Add to dashboard Cite

show abstract

“…The molecular coefficients of RF and FMN fluorescence are very close, whereas that of FAD is significantly lower (ϳ20% of the molar fluorescence of RF and FMN) due to fluorescence quenching by the adenylic moiety (204). Irradiation of flavins leads to their decomposition, producing derivatives with totally or partially degraded ribityl chains; lumiflavin (7,8,10-trimethylisoalloxazine) is accumulated in alkaline solutions, whereas lumichrom (7,8- (33,374).…”

Section: Chemical Structure and Propertiesmentioning

confidence: 99%

“…The role of purine compounds as precursors of RF was known from the works of Goodwin in the middle of the 20th century (150). The carbon atom of the purine precursor and all carbon atoms of the pyrimidine ring were incorporated into the RF molecule (7). Later it was established that some guanylic compound at the nucleoside or nucleotide level acts as precursor of RF and that this ribose moiety of the purine precursor is transferred to the ribityl side chain of RF (18,27,272,282).…”

Section: Biochemical Pathways Of Riboflavin Synthesis In Bacteria Fumentioning

confidence: 99%

Genetic Control of Biosynthesis and Transport of Riboflavin and Flavin Nucleotides and Construction of Robust Biotechnological Producers

Abbas

Sibirny

2011

Microbiol Mol Biol Rev

316

272

View full text Add to dashboard Cite

SUMMARY Riboflavin [7,8-dimethyl-10-(1′- d -ribityl)isoalloxazine, vitamin B 2 ] is an obligatory component of human and animal diets, as it serves as the precursor of flavin coenzymes, flavin mononucleotide, and flavin adenine dinucleotide, which are involved in oxidative metabolism and other processes. Commercially produced riboflavin is used in agriculture, medicine, and the food industry. Riboflavin synthesis starts from GTP and ribulose-5-phosphate and proceeds through pyrimidine and pteridine intermediates. Flavin nucleotides are synthesized in two consecutive reactions from riboflavin. Some microorganisms and all animal cells are capable of riboflavin uptake, whereas many microorganisms have distinct systems for riboflavin excretion to the medium. Regulation of riboflavin synthesis in bacteria occurs by repression at the transcriptional level by flavin mononucleotide, which binds to nascent noncoding mRNA and blocks further transcription (named the riboswitch). In flavinogenic molds, riboflavin overproduction starts at the stationary phase and is accompanied by derepression of enzymes involved in riboflavin synthesis, sporulation, and mycelial lysis. In flavinogenic yeasts, transcriptional repression of riboflavin synthesis is exerted by iron ions and not by flavins. The putative transcription factor encoded by SEF1 is somehow involved in this regulation. Most commercial riboflavin is currently produced or was produced earlier by microbial synthesis using special selected strains of Bacillus subtilis , Ashbya gossypii , and Candida famata . Whereas earlier RF overproducers were isolated by classical selection, current producers of riboflavin and flavin nucleotides have been developed using modern approaches of metabolic engineering that involve overexpression of structural and regulatory genes of the RF biosynthetic pathway as well as genes involved in the overproduction of the purine precursor of riboflavin, GTP.

show abstract

“…This indicates that the nongrowing cells of E. ashbyii behave like a mutant lacking GMP reductase which converts GMP to IMP, although the growing cells of the mold revealed the activity of GMP re ductase (23 -dihydroxypyrimidine isolated from the mycelia of Eremothecium ashbyii in the presence of glyoxal or dimeric diacetyl as trapping agents.…”

Section: Discussionmentioning

confidence: 99%

The immediate nucleotide precursor, guanosine triphosphate, in the riboflavin biosynthetic pathway.

Mitsuda

Nakajima

Nadamoto

1977

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

View full text Add to dashboard Cite

Studies on the biosynthesis of riboflavin. 7. The incorporation of adenine and guanine into riboflavin and into nucleic acid purines in Eremothecium ashbyii and Candida flareri

Cited by 24 publications

References 16 publications

Development of Specific Experimental Systems for Flavinogenesis Using Non-Growing Cell of Eremothecium ashbyii

Development of Specific Experimental Systems for Flavinogenesis Using Non-Growing Cell of Eremothecium ashbyii

Genetic Control of Biosynthesis and Transport of Riboflavin and Flavin Nucleotides and Construction of Robust Biotechnological Producers

The immediate nucleotide precursor, guanosine triphosphate, in the riboflavin biosynthetic pathway.

Contact Info

Product

Resources

About