Participation of exogenous thymine and thymidine in deoxyribonucleic acid synthesis in <i>Lactobacillus acidophilus</i>

Sawula, R. V.; Zamenhof, Stephen; Zamenhof, Patrice J.

doi:10.1139/m75-071

Cited by 5 publications

(3 citation statements)

References 16 publications

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“…seems unlikely. Thymine has been found to be a very poor DNA precursor in this strain (14), and there is little reason to suppose that uracil would be a better precursor than thymine under these conditions.…”

Section: Resultsmentioning

confidence: 85%

Incorporation of deoxycytidine into deoxyribonucleic acid deoxycytidylate in Lactobacillus acidophilus R-26

Davis¹,

Ives²

1976

J Bacteriol

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Lactobacillus acidophilus R-26, a strain deficient in ribonucleotide reductase, was grown with [G-'4C]deoxycytidine as the only source of deoxyribose in the medium. Of the radioactivity incorporated into deoxyribonucleic acid, a fifth moved directly into deoxyribonucleic acid deoxycytidylate, without deamination. Furthermore, deoxycytidine and thymidine nucleotides had similar sugar/ base ratios, suggesting a direct conversion of deoxycytidine nucleotides to thymidine nucleotides through deamination, without further dilution by glycosyl transfer. Although radioactivity was incorporated into both the sugar and base moieties of deoxyribonucleic acid pyrimidine deoxyribonucleotides, only the sugar moiety of purine deoxyribonucleotides was labeled. Purine deoxyribonucleotides probably were synthesized by glycosyl transfer from [G-'4C]deoxycytidine to unlabeled purines, followed by phosphorylation of the deoxynucleotides.

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Section: Resultsmentioning

confidence: 85%

Incorporation of deoxycytidine into deoxyribonucleic acid deoxycytidylate in Lactobacillus acidophilus R-26

Davis¹,

Ives²

1976

J Bacteriol

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“…This observation supported the assumption that they were devoid of pyrimidine phosphorylases. However, in 1974, a thymidine phosphorylase activity was found in Lactobacillus acidophilus [15][16]. We have recently observed a similar activity in Lactobacillus casei [17].…”

Section: Introductionmentioning

confidence: 88%

Thymidine phosphorylase and uridine phosphorylase of Lactobacillus casei

Avraham

Yashphe

Grossowicz

1988

FEMS Microbiology Letters

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SUMMARYCrude extracts of Lactobacillus casei, were found to possess both thymidine phosphorylase and uridine phosphorylase activities, which were associated with a single sucrose gradient band. However, using dye ligand chromatography (Green A), two enzymatic fractions were obtained each of which possessed mainly one of these activities. By this procedure, the uridine phosphorylase was purified 329-fold and the thymidine phosphorylase about 25-fold. The existence of the two phosphorylases was supported by Kin, K~, pH optimum, and heat stability studies. Identical bands were obtained on sucrose gradient sedimentation for the purified enzymes and for their mixture in a crude extract, suggesting that they have similar sedimentation coefficients, and do not form an aggregate in the crude extract.

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“…Unlike most bacteria, lactobacilli possess a trans-N-deoxyribosylase (trans-N-glycosidase, EC 2.4.2.6) which catalyzes a phosphate independent direct transfer of deoxyribose moieties between a wide variety of purines and pyrimidines [13,14]. However, in 1974, a thymidine phosphorylase activity was found in Lactobacillus acidophilus [15][16]. However, in 1974, a thymidine phosphorylase activity was found in Lactobacillus acidophilus [15][16].…”

Section: Introductionmentioning

confidence: 99%

Thymidine phosphorylase and uridine phosphorylase of Lactobacillus casei

Avraham

1988

FEMS Microbiology Letters

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Crude extracts of Lactobacillus casei, were found to possess both thymidine phosphorylase and uridine phosphorylase activities, which were associated with a single sucrose gradient band. However, using dye ligand chromatography (Green A), two enzymatic fractions were obtained each of which possessed mainly one of these activities. By this procedure, the uridine phosphorylase was purified 329‐fold and the thymidine phosphorylase about 25‐fold. The existence of the two phosphorylases was supported by Km, Ki, pH optimum, and heat stability studies. Identical bands were obtained on sucrose gradient sedimentation for the purified enzymes and for their mixture in a crude extract, suggesting that they have similar sedimentation coefficients, and do not form an aggregate in the crude extract.

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Participation of exogenous thymine and thymidine in deoxyribonucleic acid synthesis in Lactobacillus acidophilus

Cited by 5 publications

References 16 publications

Incorporation of deoxycytidine into deoxyribonucleic acid deoxycytidylate in Lactobacillus acidophilus R-26

Incorporation of deoxycytidine into deoxyribonucleic acid deoxycytidylate in Lactobacillus acidophilus R-26

Thymidine phosphorylase and uridine phosphorylase of Lactobacillus casei

Thymidine phosphorylase and uridine phosphorylase of Lactobacillus casei

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