Linked Life Data

3162032

Source:http://linkedlifedata.com/resource/pubmed/id/3162032

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1985-10-9
pubmed:abstractText
Previous studies of phenylalanyl-tRNA synthetase expression in Escherichia coli strongly suggested that the pheS, T operon was regulated by a phenylalanine-mediated attenuation mechanism. To investigate the functions of the different segments composing the pheS, T attenuator site, a series of insertion, deletion and point mutations in the pheS, T leader region have been constructed in vitro on a recombinant M13 phage. The effects of these alterations on the regulation of the operon were measured after transferring each mutation onto a lambda phage carrying a pheS, T-lacZ fusion. The behaviours of the various mutants agree with the predictions of the attenuation model. The role of the antiterminator (2-3 pairing) as competitor of the terminator (3-4 pairing) is demonstrated by several mutations affecting the stability of the 2-3 base-pairing. The existence of deletions and point mutations in the 3-4 base-pairing shows that the terminator is essential for both expression level and regulation of the operon. Mutations in the translation initiation site of the leader peptide show that the expression of the leader peptide is essential for attenuation control. However, alteration of the translation initiation rate of the leader peptide derepresses the pheS, T operon, which is the opposite of what is observed with the trp operon. This difference is explained in terms of different translation initiation efficiencies of the leader peptides. Finally, insertion mutations, increasing gradually the distance between the leader peptide stop codon and the first strand of the antiterminator, derepress the pheS, T operon and show that formation of the antiterminator structure is under the control of the translation of the leader peptide.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
184
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31-44
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Control of phenylalanyl-tRNA synthetase genetic expression. Site-directed mutagenesis of the pheS, T operon regulatory region in vitro.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't