| RRC ID |
33560
|
| Author |
Tojo S, Satomura T, Kumamoto K, Hirooka K, Fujita Y.
|
| Title |
Molecular mechanisms underlying the positive stringent response of the Bacillus subtilis ilv-leu operon, involved in the biosynthesis of branched-chain amino acids.
|
| Journal |
J Bacteriol
|
| Abstract |
Branched-chain amino acids are the most abundant amino acids in proteins. The Bacillus subtilis ilv-leu operon is involved in the biosynthesis of branched-chain amino acids. This operon exhibits a RelA-dependent positive stringent response to amino acid starvation. We investigated this positive stringent response upon lysine starvation as well as decoyinine treatment. Deletion analysis involving various lacZ fusions revealed two molecular mechanisms underlying the positive stringent response of ilv-leu, i.e., CodY-dependent and -independent mechanisms. The former is most likely triggered by the decrease in the in vivo concentration of GTP upon lysine starvation, GTP being a corepressor of the CodY protein. So, the GTP decrease derepressed ilv-leu expression through detachment of the CodY protein from its cis elements upstream of the ilv-leu promoter. By means of base substitution and in vitro transcription analyses, the latter (CodY-independent) mechanism was found to comprise the modulation of the transcription initiation frequency, which likely depends on fluctuation of the in vivo RNA polymerase substrate concentrations after stringent treatment, and to involve at least the base species of adenine at the 5' end of the ilv-leu transcript. As discussed, this mechanism is presumably distinct from that for B. subtilis rrn operons, which involves changes in the in vivo concentration of the initiating GTP.
|
| Volume |
190(18)
|
| Pages |
6134-47
|
| Published |
2008-9-1
|
| DOI |
10.1128/JB.00606-08
|
| PII |
JB.00606-08
|
| PMID |
18641142
|
| PMC |
PMC2546780
|
| MeSH |
Adenosine / analogs & derivatives
Adenosine / metabolism
Amino Acids, Branched-Chain / biosynthesis*
Amino Acids, Branched-Chain / genetics*
Bacillus subtilis / genetics
Bacillus subtilis / metabolism*
Bacterial Proteins / genetics
Bacterial Proteins / metabolism
Base Sequence
DNA-Binding Proteins / genetics
DNA-Binding Proteins / metabolism
Gene Expression Regulation, Bacterial*
Genes, Reporter
Ligases / genetics
Ligases / metabolism
Lysine / metabolism
Operon*
Promoter Regions, Genetic
Repressor Proteins / genetics
Repressor Proteins / metabolism
Ribonucleotides / metabolism
Sequence Deletion
Transcription, Genetic
|
| IF |
3.006
|
| Times Cited |
36
|
|
WOS Category
|
MICROBIOLOGY
|
| Resource |
| Prokaryotes B. subtilis |
MBS241
MBS261
MBS262
MBS298
MBS307
MBS309
MBS310 |
