Linked Life Data

9783

Source:http://linkedlifedata.com/resource/pubmed/id/9783

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1976-12-1
pubmed:abstractText
Several types of 4-fluorophenylalanine resistant mutants were isolated. In one type of mutant DAHP synthetase (tyr) and prephenate dehydrogenase were coordinately derepressed. The mutation was linked to aroF and tyrA and was cis- dominant by merodiploid analysis, thus confirming that it is an operator constitutive mutation (tyrOc). A second type of mutation showed highly elevated levels of tyrosine pathway enzymes which were not repressed by L-tyrosine. It was unlinked to tyrA and aroF, and was trans-recessive in merodiploids. These properties were attributed to a mutation in a regulator gene, tyrR (linked to pyr F), that resulted in altered or non-functional aporepressor. Hence tyrO, tyrA, and aroF constitute an operon regulated by tyrR. In a third type of mutation chorismate mutase P-prephenate dehydratase was highly elevated. It was not linked to pheA, was located in the 95--100 min region of the Salmonella chromosome, and was recessive to the wild type gene in merodiploids. A mutation was, therefore, indicated in a regulatory gene, pheR, which specified an aporepressor for regulating pheA. DAHP synthetase (phe), specified by aroG, was not regulated by pheR, but was derepressed in one of the tyrR mutants, suggesting that as in Escherichia coli tyrR may regulate DAHP synthetase(phe) and DAHP synthetase (tyr) with the same aporepressor. A novel mutation in chorismate mutase is described.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0001-6187
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-70
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Regulation of tyrosine and phenylalanine biosynthesis in Salmonella.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.