Biomaterial Database

Regulation of ornithine decarboxylase activity by guanine nucleotides: in vivo test in potassium-depleted Escherichia coli. 1976

T T Sakai, and S S Cohen

The observation that guanosine 5'-triphosphate (GTP) is an activator and guanosine 5'-diphosphate-3'-diphosphate (ppGpp) is an inhibitor of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) of Escherichia coli [E. Hölttä et al. (1974) Biochem. Biophys. Res. Commun. 59, 1104-1111] has been confirmed. The hypothesis that synthesis of both polyamine and RNA in E. coli is regulated in vivo by these nucleotides was tested in E. coli B-207. On transfer of this K+-requiring, amino-acid-deficient strigent strain from K+-medium to Na+-medium, the organism stops protein synthesis, maintains a high rate of RNA synthesis, and increases putrescine synthesis from ornithine manyfold. Under these conditions, the cells do not markedly change their contents of GTP and ppGpp. The proposed mechanism of regulation of RNA and putrescine synthesis by guanine nucleotides does not appear to explain the metabolic phenomena observed in this organism during K+ deficiency. Nevertheless, amino acid depletion in K+-medium does result in a marked increase in ppGpp.

UI	MeSH Term	Description	Entries
D009955	Ornithine Decarboxylase	A pyridoxal-phosphate protein, believed to be the rate-limiting compound in the biosynthesis of polyamines. It catalyzes the decarboxylation of ornithine to form putrescine, which is then linked to a propylamine moiety of decarboxylated S-adenosylmethionine to form spermidine.	Ornithine Carboxy-lyase,Carboxy-lyase, Ornithine,Decarboxylase, Ornithine,Ornithine Carboxy lyase
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011700	Putrescine	A toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine.	1,4-Butanediamine,1,4-Diaminobutane,Tetramethylenediamine,1,4 Butanediamine,1,4 Diaminobutane
D002262	Carboxy-Lyases	Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.	Carboxy-Lyase,Decarboxylase,Decarboxylases,Carboxy Lyase,Carboxy Lyases
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D006150	Guanine Nucleotides		Guanine Nucleotide,Guanosine Phosphates,Nucleotide, Guanine,Nucleotides, Guanine,Phosphates, Guanosine
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial