Genetic evidence for a repressor of synthesis of cytosine deaminase and purine biosynthesis enzymes in Escherichia coli

Kilstrup, Mogens; Meng, Li Mei; Neuhard, Jan; Nygaard, Per

doi:10.1128/jb.171.4.2124-2127.1989

Cited by 88 publications

(64 citation statements)

References 12 publications

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“…At present only the regulation of codA has been investigated. For the expression of this gene, purine repression [25] and nitrogen control are observed along with pyrimidine repression [26]. The expression of the udk and upp genes increase upon pyrimidine starvation [l].…”

Section: Discussionmentioning

confidence: 99%

Characterization of the upp gene encoding uracil phosphoribosyltransferase of Escherichia coli K12

Andersen¹,

Smith²,

Mygind³

1992

European Journal of Biochemistry

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The upp gene coding for uracil phosphoribosyltransferase was subcloned on a 5‐kb EcoRI restriction fragment along with the purMN operon. By a combination of complementation, deletion and minicell analyses, the upp gene was located adjacent to and divergently transcribed from the purMN operon. All three gene products could be identified in minicell extracts. The cloned upp gene shows an elevated expression upon uracil starvation. The nucleotide sequence and transcription start of the gene were determined. The sequence yields an open reading frame of 624 nucleotides encoding a protein of 22.5 kDa which is in agreement with the previously determined subunit Mr of the purified enzyme. A putative 5‐phosphoribosyl‐α‐1‐diphosphate (PRPP) binding site has been identified which is similar to the PRPP binding site of the yeast uracil phosphoribosyltransferase.

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Section: Discussionmentioning

confidence: 99%

Characterization of the upp gene encoding uracil phosphoribosyltransferase of Escherichia coli K12

Andersen¹,

Smith²,

Mygind³

1992

European Journal of Biochemistry

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“…Lrp's role in gcv regulation appears to be structural, binding and bending the DNA to facilitate the formation of the appropriate regulatory complexes for activation or repression of the operon , although the possibility that Lrp also activates transcription through interactions with RNA polymerase (RNAP) or a second regulatory protein has not been completely ruled out. PurR, a repressor for numerous genes involved in nucleotide metabolism (Kilstrup et al, 1989 ;Rolfes & Zalkin, 1988), mediates a twofold decrease in gcv transcription in the presence of exogenous purines Wilson et al, 1993a). PurR binds to the gcv control region from bp k3 to j17 relative to the transcription start site ( Fig.…”

Section: Introductionmentioning

confidence: 99%

Glycine binds the transcriptional accessory protein GcvR to disrupt a GcvA/GcvR interaction and allow GcvA-mediated activation of the Escherichia coli gcvTHP operon

Heil

Stauffer

2002

Microbiology

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The Escherichia coli gcvTHP operon is under control of the LysR-type transcriptional regulator GcvA. GcvA activates the operon in the presence of glycine and represses the operon in its absence. Repression by GcvA is dependent on a second regulatory protein, GcvR. Generally, LysR-type transcriptional regulators bind to specific small co-effector molecules which results in either their altered affinity for specific binding sites on the DNA or altered ability to bend the DNA, resulting in either activation or repression of their respective operons. This study shows that glycine, the co-activator for the gcv operon, does not alter either GcvA's ability to bind DNA nor its ability to bend DNA. Rather, glycine binds to GcvR, disrupting a GcvA/GcvR interaction required for repression and allowing GcvA activation of the gcvTHP operon. Amino acid changes in GcvR that reduce glycine binding result in a loss of glycine-mediated activation in vivo.

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“…The genes of the purine biosynthetic pathway are regulated by a common repressor protein (PurR) (13,20). This protein responds to a variety of purines (19), but no regulation by thiamine has been noticed (22a).…”

mentioning

confidence: 99%

Evidence for a new, oxygen-regulated biosynthetic pathway for the pyrimidine moiety of thiamine in Salmonella typhimurium

Downs

1992

J Bacteriol

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The synthesis of the pyrimidine moiety of thiamine (vitamin B1) shares five reactions with the de novo purine biosynthetic pathway. Aminoimidazole ribotide (AIR) is the last common intermediate before the two pathways diverge. Evidence for the existence of a new pathway to the pyrimidine which bypasses the de novo purine biosynthetic pathway is reported here. This pathway is only expressed under anaerobic growth conditions and is denoted alternative pyrimidine biosynthesis or APB. Labeling studies are consistent with pantothenate being a precursor to the pyrimidine moiety of thiamine that is synthesized by the APB pathway. The APB pathway is independent of the alternative purF function which was proposed previously (D. M. Downs and J. R. Roth, J. Bacteriol. 173:6597-6604, 1991). The alternative purF function is shown here to be affected by temperature and exogenous pantothenate. Although the evidence suggests that the APB pathway is separate from the alternative purF function, the relationship between this function and the APB pathway is not yet clear.

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Genetic evidence for a repressor of synthesis of cytosine deaminase and purine biosynthesis enzymes in Escherichia coli

Cited by 88 publications

References 12 publications

Characterization of the upp gene encoding uracil phosphoribosyltransferase of Escherichia coli K12

Characterization of the upp gene encoding uracil phosphoribosyltransferase of Escherichia coli K12

Glycine binds the transcriptional accessory protein GcvR to disrupt a GcvA/GcvR interaction and allow GcvA-mediated activation of the Escherichia coli gcvTHP operon

Evidence for a new, oxygen-regulated biosynthetic pathway for the pyrimidine moiety of thiamine in Salmonella typhimurium

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