Premium
Escherichia coli leucine‐responsive regulatory protein (Lrp) controls lysyl‐tRNA synthetase expression
Author(s) -
Gazeau Myriam,
Delort Florence,
Dessen Philippe,
Blanquet Sylvain,
Plateau Pierre
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80857-d
Subject(s) - escherichia coli , transfer rna , leucine , chemistry , biochemistry , biology , amino acid , rna , gene
Using random Tn 10 insertion mutagenesis, we isolated an Escherichia coli mutant strain affected in the regulation of lysU , the gene encoding the inducible form of lysyl‐tRNA synthetase. The transposon giving rise to the altered expression of lysU was found inserted within lrp . The latter gene codes for the leucine‐responsive regulatory protein (Lrp) which mediates a global response of the bacterium to leucine. An involvement of Lrp in the regulation of lysU was searched for by using a lysU‐lacZ operon fusion. The following conclusions were reached: (i) inactivation of lrp causes an increased activity of the lysU promoter, whatever the growth conditions assayed, (ii) insertion of a wild‐type lrp gene into a multi‐copy plasmid significantly reduces lysU expression, and (iii) sensitivity of the lysU promoter to the presence of leucine in the growth medium is abolished in the lrp context.