Linked Life Data

6280023

Source:http://linkedlifedata.com/resource/pubmed/id/6280023

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1982-6-24
pubmed:abstractText
A positive method is proposed for selecting Pichia guilliermondii mutants with derepressed GTP cyclohydrolase. Mutants with the incompletely blocked gene RIB2 were used as parent strains; these can grow in a medium without riboflavin (RF) only if the enzyme is derepressed as the result of iron deficiency in cells. Strains growing in a medium without RF at the optimal supply of cells with iron were selected as regulatory mutants. The mutants accumulated 6,7-dimethylpterin in high concentrations and a small amount of RF in the medium and in the cells. The activity of GTP cyclohydrolase rather than that of RF synthase increased in the mutants; the activity of RF kinase and FAD pyrophosphorylase was not elevated. Hybrids produced by crossing the regulatory mutants with wild type strains did not accumulate 6,7-dimethylpterin in the medium and the activity of the GTP cyclohydrolase did not increase; this is indicative of the negative regulation for the expression of the structural gene for GTP cyclohydrolase. The authors propose a model for the regulation of GTP cyclohydrolase and RF synthase at the gene level involving iron ions as a corepressor.
pubmed:language
rus
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0026-3656
pubmed:author
pubmed:issnType
Print
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
96-101
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:articleTitle
[Selection and mutant properties of Pichia guilliermondii yeasts with derepressed GTP cyclohydrolase, the enzyme of the 1st step in flavinogenesis].
pubmed:publicationType
Journal Article, English Abstract