Linked Life Data

7730362

Source:http://linkedlifedata.com/resource/pubmed/id/7730362

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1995-6-1
pubmed:abstractText
The proline utilization (put) operon from Salmonella typhimurium consists of the putP gene, encoding a proline transporter, and the putA gene, encoding an enzyme with both proline dehydrogenase and 1-pyrroline-5-carboxylate dehydrogenase activities. In addition to these two enzymatic activities, the PutA protein is a transcriptional repressor that regulates the expression of putP and putA in response to the availability of proline. We report the isolation of super-repressor mutants of PutA that decrease expression from the putA promoter in the presence or absence of proline. None of the mutants exhibited increased affinity for the DNA in the put regulatory region in vitro. Although DNA binding by wild-type PutA was prevented by the addition of proline and an artificial electron acceptor, DNA binding by the two strongest super-repressors was not prevented under identical conditions. The proline dehydrogenase activity of the purified mutant proteins showed altered kinetic properties (increased Km(Pro), reduced Vmax, or a completely null phenotype). The observation that these mutations simultaneously affect induction by proline and proline dehydrogenase activity suggests that a single proline-binding site is involved in both proline dehydrogenase activity and induction of the expression of the put operon. Furthermore, the results indicate that the proline dehydrogenase activity of PutA is essential for induction of the put operon by proline.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
270
pubmed:geneSymbol
putA, putP
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9819-27
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Proline dehydrogenase activity of the transcriptional repressor PutA is required for induction of the put operon by proline.
pubmed:affiliation
Department of Microbiology, University of Illinois at Urbana-Champaign 61801, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't