Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1972-2-2
pubmed:abstractText
Phosphoribosylpyrophosphate (PRPP) synthetase participates in the biosynthesis in bacteria of purine nucleotides, pyrimidine nucleotides, tryptophan, and histidine. The regulation of the synthesis of PRPP synthetase in Salmonella typhimurium was studied. Addition of end products to the growth medium, singly or in combination, resulted in small decreases in the specific activity of PRPP synthetase, but levels of the enzyme were never decreased to less than half of those found when the bacteria were grown on minimal medium. Growth of the bacteria on several different carbon sources or starvation for phosphate had little effect on the specific activity of PRPP synthetase. Over-production of histidine in a histidine regulatory mutant, which would be expected to result in a depletion of intracellular PRPP pools, did not alter PRPP synthetase specific activity. PRPP synthetase levels were examined in auxotrophic strains of S. typhimurium that had been starved for the end products of PRPP. In each case derepression of an enzyme in the biosynthetic pathway for the limiting end product was demonstrated. However, only alterations in the levels of pyrimidine bases in the culture medium brought about derepression and repression of PRPP synthetase. Excess pyrimidines do not completely repress the enzyme. Deprivation of exponentially growing cells for pyrimidines by growth of an auxotrophic mutant on media containing orotic acid, which enters the cells slowly, resulted in a 10-fold derepression of PRPP synthetase. Derepression of PRPP synthetase during uracil starvation was prevented by chloramphenicol. The PRPP synthetase activities of extracts from repressed and derepressed cells responded in identical fashion to heat inactivation, cellulose acetate electrophoresis at several pH values, and in kinetic experiments.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13278318, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13328894, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13428767, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13462990, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13563519, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13563527, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13682989, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13761395, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13793162, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13890281, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-13959618, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-14392174, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-14907713, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4306285, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4389471, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4866376, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4874308, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4876137, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4887363, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4889221, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4889467, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-4908668, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-5333199, http://linkedlifedata.com/resource/pubmed/commentcorrection/4330734-5361395
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adenine, http://linkedlifedata.com/resource/pubmed/chemical/Adenosine, http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Aspartic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Culture Media, http://linkedlifedata.com/resource/pubmed/chemical/Histidine, http://linkedlifedata.com/resource/pubmed/chemical/Nucleotides, http://linkedlifedata.com/resource/pubmed/chemical/Oxidoreductases, http://linkedlifedata.com/resource/pubmed/chemical/Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/Phosphoric Monoester Hydrolases, http://linkedlifedata.com/resource/pubmed/chemical/Phosphorus Isotopes, http://linkedlifedata.com/resource/pubmed/chemical/Phosphotransferases, http://linkedlifedata.com/resource/pubmed/chemical/Transferases, http://linkedlifedata.com/resource/pubmed/chemical/Tryptophan, http://linkedlifedata.com/resource/pubmed/chemical/Uridine
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9193
pubmed:author
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
122-31
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed-meshheading:4330734-Adenine, pubmed-meshheading:4330734-Adenosine, pubmed-meshheading:4330734-Adenosine Triphosphate, pubmed-meshheading:4330734-Aspartic Acid, pubmed-meshheading:4330734-Cell-Free System, pubmed-meshheading:4330734-Culture Media, pubmed-meshheading:4330734-Enzyme Repression, pubmed-meshheading:4330734-Fluorometry, pubmed-meshheading:4330734-Histidine, pubmed-meshheading:4330734-Nucleotides, pubmed-meshheading:4330734-Oxidoreductases, pubmed-meshheading:4330734-Phosphates, pubmed-meshheading:4330734-Phosphoric Monoester Hydrolases, pubmed-meshheading:4330734-Phosphorus Isotopes, pubmed-meshheading:4330734-Phosphotransferases, pubmed-meshheading:4330734-Salmonella typhimurium, pubmed-meshheading:4330734-Transferases, pubmed-meshheading:4330734-Tryptophan, pubmed-meshheading:4330734-Uridine
pubmed:year
1971
pubmed:articleTitle
Regulation and mechanism of phosphoribosylpyrophosphate synthetase: repression by end products.
pubmed:publicationType
Journal Article