Inhibition of glutamine synthetase II expression by the product of the gstI gene.
Mol Microbiol
; 37(2): 443-52, 2000 Jul.
Article
in En
| MEDLINE
| ID: mdl-10931338
ABSTRACT
We report the identification of a previously unrecognized gene that is involved in the regulation of the Rhizobium leguminosarum glnII (glutamine synthetase II) gene. This gene, which is situated immediately upstream of glnII, was identified by means of a deletion/complementation analysis performed in the heterologous background of Klebsiella pneumoniae. It has been designated gstI (glutamine synthetase translational Inhibitor) because, when a complete version of gstI is present, it is possible to detect glnII-specific mRNA, but neither GSII activity nor GSII protein. The gstI gene encodes a small (63 amino acids) protein, which acts in cis or in trans with respect to glnII and is transcribed divergently with respect to glnII from a promoter that was found to be strongly repressed by the nitrogen transcriptional regulator NtrC. A mutated version of GstI lacking the last 14 amino acids completely lost its capacity to repress glnII expression. Our results indicate that gstI mediates the translation inhibition of glnII mRNA and, based on in silico analyses, a mechanism for GstI action is proposed.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Repressor Proteins
/
Bacterial Proteins
/
Transcription Factors
/
Gene Expression Regulation, Bacterial
/
Rhizobium leguminosarum
/
Glutamate-Ammonia Ligase
Type of study:
Prognostic_studies
Language:
En
Journal:
Mol Microbiol
Journal subject:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Year:
2000
Document type:
Article
Affiliation country:
Italia