Biomaterial Database

The purification and properties of deoxyguanosine triphosphate triphosphohydrolase from Escherichia coli. 1988

D Seto, and S K Bhatnagar, and M J Bessman

McCollum-Pratt Institute, Baltimore, Maryland.

Deoxyguanosine triphosphate (dGTP) triphosphohydrolase (EC 3.1.5.1) has been purified approximately 16,000-fold to apparent homogeneity from extracts of Escherichia coli. The enzyme has a native molecular weight of 230,000 and a sedimentation coefficient of 9.3 S. Its subunit molecular weight derived from electrophoresis in denaturing polyacrylamide gels is 58,900, and it has a unique N-terminal sequence for the first 25 amino acids, which indicate that the native enzyme is composed of 4 homologous subunits. It is insensitive to sulfhydryl reagents and EDTA and can be heated to 60 degrees C for 60 min without loss of activity. The enzyme requires Mg2+ for activity, is highly specific for dGTP among the canonical deoxynucleoside triphosphates, and has a unique activity among nucleoside triphosphatases in that the products of the reaction are deoxyguanosine and inorganic tripolyphosphate. Preliminary evidence suggest that this enzyme is responsible for the optA mutant phenotype first described by Saito and Richardson (Saito, H., and Richardson, C.C. (1981) J. Virol. 37, 343-351).

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009711	Nucleotides	The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)	Nucleotide
D010744	Phosphoric Monoester Hydrolases	A group of hydrolases which catalyze the hydrolysis of monophosphoric esters with the production of one mole of orthophosphate.	Phosphatase,Phosphatases,Phosphohydrolase,Phosphohydrolases,Phosphomonoesterase,Phosphomonoesterases,Phosphoric Monoester Hydrolase,Hydrolase, Phosphoric Monoester,Hydrolases, Phosphoric Monoester,Monoester Hydrolase, Phosphoric
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
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities