Raymond Cunin

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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], is cumulatively repressed by arginine and the pyrimidines. We describe the structure of the control region of carAB and the(More)
The nucleotide sequences of the genes encoding the enzyme aspartate transcarbamoylase (ATCase) from Pseudomonas putida have been determined. Our results confirm that the P. putida ATCase is a dodecameric protein composed of two types of polypeptide chains translated coordinately from overlapping genes. The P. putida ATCase does not possess dissociable(More)
Forty-four sequences of ornithine carbamoyltransferases (OTCases) and 33 sequences of aspartate carbamoyltransferases (ATCases) representing the three domains of life were multiply aligned and a phylogenetic tree was inferred from this multiple alignment. The global topology of the composite rooted tree (each enzyme family being used as an outgroup to root(More)
The 12 genes which in E. coli K-12 constitute the arginine regulon are organized in nine transcriptional units all of which contain in their 5' non-coding region two 18 bp partially conserved imperfect palindromes (ARG boxes) which are the target sites for binding of the repressor, a hexameric protein. In vitro binding experiments with purified repressor (a(More)
The pattern of divergent transcription of the argECBH cluster of genes previously demonstrated by the hybridization of RNA to the separated strand of a ϕ80 drag transducing phage, is confirmed with the DNA of a set of different λdarg phages. The accurate determination of argE and argCBH m-RNA levels in different steady states of expression of the arg(More)
Pyrococcus abyssi, a hyperthermophilic archaeon found in the vicinity of deep-sea hydrothermal vents, grows optimally at temperatures around 100°C. Carbamoyl phosphate synthetase (CPSase) from this organism was cloned and sequenced. The active 34-kDa recombinant protein was overexpressed in Escherichia coli when the host cells were cotransformed with a(More)
The accumulation or ornithine, citrulline, and possibly acetylornithine by Escherichia coli K-12 arginineless mutants provided with acetylarginine as source of arginine causes severe growth inhibition. This occurs under conditions where comparable derivatives of E. coli W (Bollon and Vogel, 1973) show little or no growth inhibition. The same conditions,(More)
In the allosteric aspartate transcarbamylase (ATCase) from the hyperthermophilic eubacterium Thermotoga maritima, the catalytic and regulatory functions, which in class B ATCases are carried out by specialized polypeptides, are combined on a single type of polypeptide assembled in trimers. The ATCases from T. maritima and Treponema denticola present(More)
A basic challenge in cell biology is to understand how interconnected metabolic pathways are regulated to provide the adequate cellular outcome when changing levels of metabolites and enzyme expression. In Escherichia coli, the arginine and pyrimidine biosynthetic pathways are connected through a common metabolite provided by a single enzyme. The different(More)