The regulatory region of the divergent<i>argECBH</i>operon in<i>Escherichia coli</i>K-12

Piette, Jacques; Cunin, Raymond; Boyen, Anne; Charlier, Daniël; Crabeel, Marjolaine; Vliet, Franc ̧oise Van; Glansdorff, Nicolas; Squires, Catherine L.

doi:10.1093/nar/10.24.8031

Cited by 52 publications

(21 citation statements)

References 47 publications

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“…1) relative to the transcription initiation site (defined by analysis both in vivo and in vitro; 15). This mutation is consistent with similar mutations previously identified as down mutations in the promoters of bacteriophage lambda (23) and of the arg operon (22). As such, they confirm that the sequence TAACTCT (-13 to -7) corresponds to the -10 region of other bacterial promoters (14).…”

supporting

confidence: 90%

Point mutations in the regulatory region of the ilvGMEDA operon of Escherichia coli K-12

Lawther

1989

J Bacteriol

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The ilvGMEDA operon of Escherichia coli K-12 is preceded by a regulatory region containing a promoter, a leader, and an attenuator. This region has been extensively characterized biochemically. In this note point mutations of the regulatory region are reported. The effect of these mutations on expression from the ilv regulatory region supports the previous biochemical analysis.The genes for biosynthesis of the branched-chain atino acids isoleucine, leucine, and valine are divided into several transcriptional units (26). The largest is the ilvGMEDA operon, which is multivalently regulated by all three amino acids (26). Limitation of the growth of either Escherichia coli K-12 or Salmonella typhimurium by deficiencies in any of the three amino acids results in derepression of the operon (6). Alternatively, the addition of all three amino acids to minimal medium results in repression of the operon (26). Eidlic and Neidhardt (5) made the first observation that ilv gene regulation is tRNA mediated by using an E. coli strain that contained a temperature-sensitive valyl-tRNA synthetase. Subsequent studies of mutant strains of S. typhimuriumn (4) and E. coli K-12 (13) with altered tRNA modification supported this conclusion. DNA sequence analysis suggested that the ilvGMEDA operon is preceded by a leaderattenuator. In both E. coli K-12 (14, 20) and S. typhimurium (25), the leader region encodes a putative 32-amino-acid polypeptide that contains 15 branched-chain amino acid residues (Fig. 1);The isolation and characterization of mutant or variant strains assisted in elucidating the mechanisms of the regulation of gene expression. Such mutants provided much insight into the regulation by attenuation of the trp (24, 28), his (10), thr (16,17), and leu (3) operons. Investigation of the regulation of the ilvGMEDA operon has been limited by the absence of mutations that alter the leader-attenuator. Comparison of the regulatory region of S. typhimurium with that of E. coli K-12 (25) indicated only seven nucleotide (nt) differences over more than 200 base pairs (bp). None of the observed nucleotide differences would be expected to affect leader-attenuator function. Harms et al. (7) also determined the DNA sequences of the regulatory regions of the ilvG4fEDA operons of E. coli B, Klebsiella aerogenes, Edwardsiella tarda, and Serratia marcescens. The nucleotide sequences for E. coli B and K. aerogenes were found to be similar to those reported for E. coli K-12 and S. typhimurium; i.e., no nucleotide changes that should alter either the secondary structure of the leader RNA or the amino acid composition of the leader peptide were observed. The nucleotide sequences determined for both Edwardsiella tarda and Serratia marcescens were found to differ substantially from those for E. coli K-12. As a result, the RNA secondary structure should change and the deduced amino acid sequence of the leader peptide should also vary. Thus, regulation of the attenuation of the ilvGMEDA operon by leucine for Edwardsiella tarda and Serratia marcesce...

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supporting

confidence: 90%

Point mutations in the regulatory region of the ilvGMEDA operon of Escherichia coli K-12

Lawther

1989

J Bacteriol

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“…(v) The -10 region of promoter P2 of carAB is included within a canonical arginine operator (11,12,22,23 GCG CTA TTG GTT CTG GAA GAC GGA ACC CAG TTT CAC GGT CGG GCC ATA GGG GCA ACA GGT TCG GCG GTT ala leu leu val leu glu asp gly thr gin phe his gly arg ala ile gly ala thr gly ser ala val Fig. 3 …”

Section: Resultsmentioning

confidence: 99%

“…of the operator site ("arginine boxes") of several other genes of the arginine regulon (11,12,22,23). argE, argCBH, argF, and argI are controlled by repressor interactions at pairs of arg boxes separated by three nucleotides (22,23); it is probably significant, therefore, that the arg box overlapping P2 is followed by a second, more degenerate one.…”

Section: Discussionmentioning

confidence: 99%

DNA sequence of the carA gene and the control region of carAB: tandem promoters, respectively controlled by arginine and the pyrimidines, regulate the synthesis of carbamoyl-phosphate synthetase in Escherichia coli K-12.

Piette¹,

Nyunoya²,

Lusty³

et al. 1984

Proc. Natl. Acad. Sci. U.S.A.

156

118

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The carAB operon of Escherichia coli K-12, which encodes the two subunits of carbamoyl-phosphate synthetase (glutamine hydrolyzing) [carbon-dioxide: L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating); EC 6.3.5.5], is cumulatively repressed by arginine and the pyrimidines. We describe the structure of the control region of carAB and the sequence of the carA gene. Nuclease S1 mapping experiments show that two adjacent tandem promoters within the carAB control region serve as initiation sites. The upstream promoter P1 is controlled by pyrimidines; the downstream promoter P2 is regulated by arginine. Attenuation control does not appear to be involved in the expression of carAB. A possible mechanism by which control at these promoters concurs to produce a cumulative pattern of repression is discussed. The translational start of carA is atypical; it consists of a UUG or AUU codon.

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“…Interestingly, two O c -type mutations isolated in the operator region of the bipolar argECBH operon consist of a G·C to A·T transition at position 14·5′. 46 Furthermore, it is also worth noticing that the symmetrical equivalent, i.e. a T·A base-pair in position 5·14′, never occurs in the 26 characterized E. coli ARG boxes.…”

Section: Discussionmentioning

confidence: 99%

ArgR-dependent Repression of Arginine and Histidine Transport Genes in Escherichia coli K-12

Caldara

Minh

Bostoen

et al. 2007

Journal of Molecular Biology

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The regulatory region of the divergentargECBHoperon inEscherichia coliK-12

Cited by 52 publications

References 47 publications

Point mutations in the regulatory region of the ilvGMEDA operon of Escherichia coli K-12

Point mutations in the regulatory region of the ilvGMEDA operon of Escherichia coli K-12

DNA sequence of the carA gene and the control region of carAB: tandem promoters, respectively controlled by arginine and the pyrimidines, regulate the synthesis of carbamoyl-phosphate synthetase in Escherichia coli K-12.

ArgR-dependent Repression of Arginine and Histidine Transport Genes in Escherichia coli K-12

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