Alternative patterns of his operon transcription and mRNA processing generated by metabolic perturbation

Alifano, Pietro; Rivellini, F.; Nappo, A. G.; Bruni, Carmelo B.; Carlomagno, Maria Stella

doi:10.1016/0378-1119(94)90828-1

Cited by 12 publications

(22 citation statements)

References 24 publications

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“…A limited number of studies suggest that intracellular formylating capacity and its modulation of initiator fMet-tRNA pools may influence his operon expression (see (7)). Premature transcript 3′ ends were mapped in the hisC region in response to the drugs trimethoprim and kasugamycin, which decrease the intracellular fMet-tRNA pool and the binding of fMet-tRNA to ribosomes, respectively, and thereby uncouple transcription and translation (7).…”

Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

“…Premature transcript 3′ ends were mapped in the hisC region in response to the drugs trimethoprim and kasugamycin, which decrease the intracellular fMet-tRNA pool and the binding of fMet-tRNA to ribosomes, respectively, and thereby uncouple transcription and translation (7). Both antibiotics lead to premature his transcript release, possibly by increasing Rho factor-dependent transcription termination within the operon (see below) and RNA polymerase pausing (7). Trimethoprim, and to a lesser extent kasugamycin, also led to an increase in his transcript processing in the hisC-hisB region (7), possibly by exposing a transcript processing site within hisC or by fostering ribosome stalling at the start of hisB (see below).…”

Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

“…Both antibiotics lead to premature his transcript release, possibly by increasing Rho factor-dependent transcription termination within the operon (see below) and RNA polymerase pausing (7). Trimethoprim, and to a lesser extent kasugamycin, also led to an increase in his transcript processing in the hisC-hisB region (7), possibly by exposing a transcript processing site within hisC or by fostering ribosome stalling at the start of hisB (see below). Another link between histidine biosynthesis and intracellular formylation involves production of AICAR (Fig.…”

Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

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Biosynthesis of Histidine

Winkler

Ramos‐Montañez²

2009

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The biosynthesis of histidine in Escherichia coli and Salmonella typhimurium has been an important model system for the study of relationships between the flow of intermediates through a biosynthetic pathway and the control of the genes encoding the enzymes that catalyze the steps in a pathway. This article provides a comprehensive review of the histidine biosynthetic pathway and enzymes, including regulation of the flow of intermediates through the pathway and mechanisms that regulate the amounts of the histidine biosynthetic enzymes. In addition, this article reviews the structure and regulation of the histidine ( his ) biosynthetic operon, including transcript processing, Rho-factor-dependent “classical” polarity, and the current model of his operon attenuation control. Emphasis is placed on areas of recent progress. Notably, most of the enzymes that catalyze histidine biosynthesis have recently been crystallized, and their structures have been determined. Many of the histidine biosynthetic intermediates are unstable, and the histidine biosynthetic enzymes catalyze some chemically unusual reactions. Therefore, these studies have led to considerable mechanistic insight into the pathway itself and have provided deep biochemical understanding of several fundamental processes, such as feedback control, allosteric interactions, and metabolite channeling. Considerable recent progress has also been made on aspects of his operon regulation, including the mechanism of pp(p)Gpp stimulation of his operon transcription, the molecular basis for transcriptional pausing by RNA polymerase, and pathway evolution. The progress in these areas will continue as sophisticated new genomic, metabolomic, proteomic, and structural approaches converge in studies of the histidine biosynthetic pathway and mechanisms of control of his biosynthetic genes in other bacterial species.

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Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

Section: Structure and Regulation Of The His Operonmentioning

confidence: 99%

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Biosynthesis of Histidine

Winkler

Ramos‐Montañez²

2009

EcoSal Plus

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“…The uncommon stability of this transcript suggests that the processing event has a functional role. In fact, the processed species spans the distal cistrons which are involved, in addition to histidine biosynthesis, in a purine recycling pathway leading to production of a cellular 'alarmone' (Alifano et al, 1994).…”

Section: The Endonucleolytic Decay Of Mrna: Functional Coupling Betwementioning

confidence: 99%

Control of mRNA processing and decay in prokaryotes

1994

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Post-transcriptional mechanisms operate in regulation of gene expression in bacteria, the amount of a given gene product being also dependent on the inactivation rate of its own message. Moreover, segmental differences in mRNA stability of polycistronic transcripts may be responsible for differential expression of genes clustered in operons. Given the absence of 5' to 3' exoribonucleolytic activities in prokaryotes, both endoribonucleases and 3' to 5' exoribonucleases are involved in chemical decay of mRNA. As the 3' to 5' exoribonucleolytic activities are readily blocked by stem-loop structures which are usual at the 3' ends of bacterial messages, the rate of decay is primarily determined by the rate of the first endonucleolytic cleavage within the transcripts, after which the resulting mRNA intermediates are degraded by the 3' to 5' exoribonucleases. Consequently, the stability of a given transcript is determined by the accessibility of suitable target sites to endonucleolytic activities. A considerable number of bacterial messages decay with a net 5' to 3' directionality. Two different alternative models have been proposed to explain such a finding, the first invoking the presence of functional coupling between degradation and the movement of the ribosomes along the transcripts, the second one implying the existence of a 5' to 3' processive '5' binding nuclease'. The different systems by which these two current models of mRNA decay have been tested will be presented with particular emphasis on polycistronic transcripts.

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The antiterminator NusB enhances termination at a sub-optimal rho site

Nappo

2001

Journal of Molecular Biology

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Alternative patterns of his operon transcription and mRNA processing generated by metabolic perturbation

Cited by 12 publications

References 24 publications

Biosynthesis of Histidine

Biosynthesis of Histidine

Control of mRNA processing and decay in prokaryotes

The antiterminator NusB enhances termination at a sub-optimal rho site

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