Histidine utilisation operon (hut) is upregulated at low temperature in the antarctic psychrotrophic bacterium Pseudomonas syringae

Kannan, K

doi:10.1016/s0378-1097(98)00043-3

Cited by 7 publications

(18 citation statements)

References 17 publications

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“…In addition, low temperature results in elevated expression of the ␣-glucan branching enzyme GlgB (YE4013) that, together with the ␣-amylase GlgX and GlgC, regulates the glycogen metabolism (56). Interestingly, the degradative hut operon, as well as an ␣-amylase, have been shown to be upregulated at low temperature in several antarctic psychrotrophic bacteria (23,36). A role of the Y. enterocolitica alkaline serine protease, a hot spot of mini-Tn5 luxCDABE insertions and a member of the extracellular subtilisin family (67), has not yet been described.…”

Section: Discussionmentioning

confidence: 99%

Transcriptional Analysis of Long-Term Adaptation ofYersinia enterocoliticato Low-Temperature Growth

et al. 2006

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To analyze the transcriptional response of Yersinia enterocolitica cells to prolonged growth at low temperature, a collection of luxCDABE transposon mutants was cultivated in parallel at optimal (30°C) and suboptimal (10°C) temperatures and screened for enhanced promoter activities during growth until entering stationary phase. Among 5,700 Y. enterocolitica mutants, 42 transcriptional units were identified with strongly enhanced or reduced promoter activity at 10°C compared to 30°C, and changes in their transcriptional levels over time were measured. Green fluorescent protein fusions to 10 promoter regions confirmed the data. The temporal order of induction of the temperature-responsive genes of Y. enterocolitica was deduced, starting with the expression of cold shock genes cspA and cspB and the elevated transcription of a glutamate-aspartate symporter. Subsequently, cold-adapted cells drastically up-regulated genes encoding environmental sensors and regulators, such as UhpABC, ArcA, and methyl-accepting chemotaxis protein I (MCPI). Among the most prominent cold-responsive elements that were transcriptionally induced during growth in early and middle exponential phase are the insecticidal toxin genes tcaA and tcaB, as well as genes involved in flagellar synthesis and chemotaxis. The expression pattern of the lateexponential-to early-stationary-growth phase is dominated by factors involved in biodegradative metabolism, namely, a histidine ammonia lyase, three enzymes responsible for uptake and utilization of glycogen, the urease complex, and a subtilisin-like protease. Double-knockout mutants and complementation studies demonstrate inhibitory effects of MCPI and UhpC on the expression of a putative hemolysin transporter. The data partially delineate the spectrum of gene expression of Y. enterocolitica at environmental temperatures, providing evidence that an as-yet-unknown insect phase is part of the life cycle of this human pathogen.

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Section: Discussionmentioning

confidence: 99%

Transcriptional Analysis of Long-Term Adaptation ofYersinia enterocoliticato Low-Temperature Growth

et al. 2006

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Section: Pseudomonadsmentioning

confidence: 93%

“…About 5% of the genes expressed at 20°C by an Antarctic psychrotrophic Pseudomonas syringae strain are expressed at significantly higher levels at 4°C (68). The histidase and urocanase genes are among them, with urocanase activity being 14-fold higher in cells grown at 4°C than at 20°C, in marked contrast to the result seen with a mesophilic pseudomonad, where a lower temperature resulted in lower urocanase activity (68). The mechanism responsible for this increased activity at low temperatures is unknown, but it operates at the transcriptional level and may reflect a cold-active promoter upstream from the normal promoter that operates at both temperatures (64).…”

Section: Pseudomonadsmentioning

confidence: 99%

Regulation of the Histidine Utilization (Hut) System in Bacteria

Bender

2012

Microbiol Mol Biol Rev

122

128

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SUMMARY The ability to degrade the amino acid histidine to ammonia, glutamate, and a one-carbon compound (formate or formamide) is a property that is widely distributed among bacteria. The four or five enzymatic steps of the pathway are highly conserved, and the chemistry of the reactions displays several unusual features, including the rearrangement of a portion of the histidase polypeptide chain to yield an unusual imidazole structure at the active site and the use of a tightly bound NAD molecule as an electrophile rather than a redox-active element in urocanase. Given the importance of this amino acid, it is not surprising that the degradation of histidine is tightly regulated. The study of that regulation led to three central paradigms in bacterial regulation: catabolite repression by glucose and other carbon sources, nitrogen regulation and two-component regulators in general, and autoregulation of bacterial regulators. This review focuses on three groups of organisms for which studies are most complete: the enteric bacteria, for which the regulation is best understood; the pseudomonads, for which the chemistry is best characterized; and Bacillus subtilis , for which the regulatory mechanisms are very different from those of the Gram-negative bacteria. The Hut pathway is fundamentally a catabolic pathway that allows cells to use histidine as a source of carbon, energy, and nitrogen, but other roles for the pathway are also considered briefly here.

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“…Neither is any information available for the in vivo recognition of promoter sequences by RNA polymerase from the cold-adapted P. syringae. Therefore, we initially attempted to identify the genes from the Antarctic P. syringae that are upregulated at low temperature, with the help of Tn5-mediated random genomic fusions of a promoter-less reporter gene, lacZ (23). One of the fusions that produced at least 10-to 14-fold more ␤-galactosidase at a low temperature (4°C) was identified by cloning and sequencing of ca.…”

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confidence: 99%

“…450 bp of DNA sequence proximal to the Tn5 insertion site. The fusion was in the hutU gene, which encodes an enzyme, urocanase, of the histidine utilization pathway of bacteria (13,23). A direct assay of urocanase activity from the P. syringae and a few more Antarctic Pseudomonas species and comparison of it with that of the mesophilic Pseudomonas putida suggested that the hutU gene is upregulated in the psychrotrophs but not in the mesophile.…”

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confidence: 99%

Cloning, Sequencing, and Expression of the Cold-Inducible hutU Gene from the Antarctic Psychrotrophic Bacterium Pseudomonas syringae

Janiyani

Ray

2002

Appl Environ Microbiol

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A promoter-fusion study with a Tn5-based promoter probe vector had earlier found that the hutU gene which encodes the enzyme urocanase for the histidine utilization pathway is upregulated at a lower temperature (4°C) in the Antarctic psychrotrophic bacterium Pseudomonas syringae. To examine the characteristics of the urocanase gene and its promoter elements from the psychrotroph, the complete hutU and its upstream region from P. syringae were cloned, sequenced, and analyzed in the present study. Northern blot and primer extension analyses suggested that the hutU gene is inducible upon a downshift of temperature (22 to 4°C) and that there is more than one transcription initiation site. One of the initiation sites was specific to the cells grown at 4°C, which was different from the common initiation sites observed at both 4 and 22°C. Although no typical promoter consensus sequences were observed in the flanking region of the transcription initiation sites, there was a characteristic CAAAA sequence at the ؊10 position of the promoters. Additionally, the location of the transcription and translation initiation sites suggested that the hutU mRNA contains a long 5-untranslated region, a characteristic feature of many cold-inducible genes of mesophilic bacteria. A comparison of deduced amino acid sequences of urocanase from various bacteria, including the mesophilic and psychrotrophic Pseudomonas spp., suggests that there is a high degree of similarity between the enzymes. The enzyme sequence contains a signature motif (GXGX 2 GX 10 G) of the Rossmann fold for dinucleotide (NAD ؉ ) binding and two conserved cysteine residues in and around the active site. The psychrotrophic enzyme, however, has an extended N-terminal end.Antarctic bacteria provide a useful model system for studying cold adaptation (15,17,31,36). These organisms are generally represented by the psychrotrophs and psychrophiles, which have the ability to grow at 0°C. They can transcribe at this lower temperature both in vitro and in vivo (31). However, nothing much is known about the nature of promoter and regulatory elements from these bacteria or about the mechanism of transcription at lower temperatures. Most of the transcriptional studies thus far have been carried out with only mesophilic bacteria, and the RNA polymerase from these bacteria, including Escherichia coli, cannot transcribe at 0°C. A recent study from our laboratory has demonstrated that the RNA polymerase of the Antarctic psychrotrophic bacterium Pseudomonas syringae can transcribe at 0°C. The polymerase from the bacterium was not only active at the low temperature but also could transcribe in vitro preferentially the cold-inducible gene of E. coli cspA from a supercoiled template (43). However, absolutely no information is available with regard to the characteristics of promoter sequence, such as the Ϫ10 and Ϫ35 elements from the bacterium for such low-temperaturespecific transcription. Neither is any information available for the in vivo recognition of promoter sequences by RNA polyme...

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Histidine utilisation operon (hut) is upregulated at low temperature in the antarctic psychrotrophic bacterium Pseudomonas syringae

Cited by 7 publications

References 17 publications

Transcriptional Analysis of Long-Term Adaptation ofYersinia enterocoliticato Low-Temperature Growth

Transcriptional Analysis of Long-Term Adaptation ofYersinia enterocoliticato Low-Temperature Growth

Regulation of the Histidine Utilization (Hut) System in Bacteria

Cloning, Sequencing, and Expression of the Cold-Inducible hutU Gene from the Antarctic Psychrotrophic Bacterium Pseudomonas syringae

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