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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-6-2
pubmed:abstractText
Several strains of Escherichia coli K12 were compared for activity of the periplasmic "pH 2.5 acid phosphatase", an enzyme whose expression is regulated negatively by cyclic AMP. Two distinct enzyme levels differing by about four-fold were observed. This strain-dependent difference does not involve modifications in the structure of the enzyme, but results from a difference in its expression. We show that strains with a high- or a low level of enzyme differ in the gene locus appR located in the 59 min region of the chromosome, a site remote from the structural gene appA; the appR+ versus appR enzyme ratio is 3-4 in wild-type strains, adenylate cyclase-deficient strains (cya) or cyclic AMP receptor protein-deficient strains (crp) grown in rich medium or in glucose minimal medium, but is close to 1 in cya strains in the presence of 0.1 mM cyclic AMP and in wild-type strains grown with succinate as carbon source; in a crp genetic background, appR strains, contrary to appR+ strains, are able to grow on minimal medium with succinate as the sole carbon source. The selection, from an appR+ crp strain, of clones growing on succinate-minimal medium, yielded mutations in the same region of the chromosome and showing the same phenotype as "naturally-occurring" appR strains. All appR strains analysed so far showed other similar deficiencies. The possibility that mutated appR gene products might function as weak substitutes for a functional cAMP-CRP complex is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:volume
202
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
257-64
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Pleiotropic mutations in appR reduce pH 2.5 acid phosphatase expression and restore succinate utilisation in CRP-deficient strains of Escherichia coli.
pubmed:publicationType
Journal Article