Regulation of the Histidine Operon: Translation-Controlled Transcription Termination (A Mechanism Common to Several Biosynthetic Operons)

Blasi, Francesco; Bruni, Carmelo B.

doi:10.1016/b978-0-12-152819-5.50018-x

Cited by 39 publications

(32 citation statements)

References 140 publications

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“…Growth on the y-glutamyl leucine peptide had the largest effect on ppGpp levels and mutation rates in CP78 (Table 3). Use of this peptide as a substitute for leucine in leu auxotrophs is assumed to be comparable to the use of histidinol or formyl histidine as substitutes for histidine in his auxotrophs (Ames & Garry, 1959;Blasi & Bruni, 1981). Growth on either of these poor sources of histidine imposes partial starvation and provokes the stringent response ; genes for the synthetic enzymes are derepressed, which could then result in increased rates of mutation.…”

Section: Discussionmentioning

confidence: 99%

Reversion rates in a leuB auxotroph of Escherichia coli K-12 correlate with ppGpp levels during exponential growth

Wright¹,

Minnick

1997

Microbiology

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Two isogenic strains of Escherichia coli K-12 differing only in relA, as well as two spoT transductants of the relA' strain, were examined with respect to ppGpp levels and reversion rates of a leuB' allele under nine different conditions. A positive correlation was established between reversion rates and the steady-state concentration of ppGpp during exponential growth. The leu6 genes from two leuB' strains (isogenic except for relA) were cloned and sequenced and found to contain a single mutation, namely, a C-to-T transition a t nucleotide 857. This mutation resulted in a serine-to-leucine substitution at amino acid residue 286 of the LeuB protein. PCR products that encompassed the leuB lesion were generated from 53 revertants and then sequenced. Of these revertants, 36 were found to contain nucleotide substitutions that would result in a serine (wild type), valine or methionine a t amino acid residue 286 of LeuB, and nearly all of them exhibited generation times similar to wild type. Seventeen of the analysed revertants were found to be suppressors that retained the encoded leucine a t residue 286. The majority of the suppressor mutants exhibited generation times that were significantly longer than wild type.

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Section: Discussionmentioning

confidence: 99%

Reversion rates in a leuB auxotroph of Escherichia coli K-12 correlate with ppGpp levels during exponential growth

Wright¹,

Minnick

1997

Microbiology

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“…In particular, in E. coli, S. typhimurium (Carlomagno et al 1988, and A. brasilense (Fani et al 1993) two of the genes, hisA and hisF, are consistently contiguous, arranged in the same order, and overlapped. Although it was early proposed that all of the histidine biosynthetic enzymes could have evolved by the duplication of a common ancestor gene (Horowitz 1965), the analysis of the nucleotide sequence of the his genes in E. coli and S. typhimurium carried out up to now has not revealed any extensive sequence homology between different genes; on the basis of the amino acid sequences, a moderate degree of similarity has been observed only for the amino-terminal regions of the hisG, hisD, and hisC polypeptides (Blasi and Bruni 1981).…”

Section: Introductionmentioning

confidence: 99%

The evolution of the histidine biosynthetic genes in prokaryotes: A common ancestor for the hisA and hisF genes

et al. 1994

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The hisA and hisF genes belong to the histidine operon that has been extensively studied in the enterobacteria Escherichia coli and Salmonella typhimurium where the hisA gene codes for the phosphoribosyl-5-amino-1-phosphoribosyl-4-imidazolecarboxamide isomerase (EC 5.3.1.16) catalyzing the fourth step of the histidine biosynthetic pathway, and the hisF gene codes for a cyclase catalyzing the sixth reaction. Comparative analysis of nucleotide and predicted amino acid sequence of hisA and hisF genes in different microorganisms showed extensive sequence homology (43% considering similar amino acids), suggesting that the two genes arose from an ancestral gene by duplication and subsequent evolutionary divergence. A more detailed analysis, including mutual information, revealed an internal duplication both in hisA and hisF genes in each of the considered microorganisms. We propose that the hisA and hisF have originated from the duplication of a smaller ancestral gene corresponding to half the size of the actual genes followed by rapid evolutionary divergence. The involvement of gene elongation, gene duplication, and gene fusion in the evolution of the histidine biosynthetic genes is also discussed.

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“…The classic example of hierarchical regulation via gene expression is the induction of the lac operon in response to lactose availability (24) or the induction of the histidine biosynthesis pathway in response to histidine limitation in the medium (25). ter Kuile and Westerhoff proposed "regulation analysis" to quantitatively resolve hierarchical from metabolic regulation (26,27). In this study, the different modes of regulation in the metabolic network of Pseudomonas putida are examined by analyzing the required metabolic and transcriptional responses to sustain growth on limiting alternative carbon sources (i.e., glucose, fructose, and benzoate).…”

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confidence: 99%

The Functional Structure of Central Carbon Metabolism in Pseudomonas putida KT2440

Sudarsan

Dethlefsen

Blank

et al. 2014

Appl Environ Microbiol

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c What defines central carbon metabolism? The classic textbook scheme of central metabolism includes the Embden-Meyerhof-Parnas (EMP) pathway of glycolysis, the pentose phosphate pathway, and the citric acid cycle. The prevalence of this definition of central metabolism is, however, equivocal without experimental validation. We address this issue using a general experimental approach that combines the monitoring of transcriptional and metabolic flux changes between steady states on alternative carbon sources. This approach is investigated by using the model bacterium Pseudomonas putida with glucose, fructose, and benzoate as carbon sources. The catabolic reactions involved in the initial uptake and metabolism of these substrates are expected to show a correlated change in gene expressions and metabolic fluxes. However, there was no correlation for the reactions linking the 12 biomass precursor molecules, indicating a regulation mechanism other than mRNA synthesis for central metabolism. This result substantiates evidence for a (re)definition of central carbon metabolism including all reactions that are bound to tight regulation and transcriptional invariance. Contrary to expectations, the canonical Entner-Doudoroff and EMP pathways sensu stricto are not a part of central carbon metabolism in P. putida, as they are not regulated differently from the aromatic degradation pathway. The regulatory analyses presented here provide leads on a qualitative basis to address the use of alternative carbon sources by deregulation and overexpression at the transcriptional level, while rate improvements in central carbon metabolism require careful adjustment of metabolite concentrations, as regulation resides to a large extent in posttranslational and/or metabolic regulation.

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Regulation of the Histidine Operon: Translation-Controlled Transcription Termination (A Mechanism Common to Several Biosynthetic Operons)

Cited by 39 publications

References 140 publications

Reversion rates in a leuB auxotroph of Escherichia coli K-12 correlate with ppGpp levels during exponential growth

Reversion rates in a leuB auxotroph of Escherichia coli K-12 correlate with ppGpp levels during exponential growth

The evolution of the histidine biosynthetic genes in prokaryotes: A common ancestor for the hisA and hisF genes

The Functional Structure of Central Carbon Metabolism in Pseudomonas putida KT2440

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