Biomaterial Database

A DNA-unwinding enzyme induced in bacteriophage-T4-infected Escherichia coli cells. 1979

H Krell, and H Dürwald, and H Hoffmann-Berling

A single-stranded DNA-dependent ATP gamma-phosphohydrolase of Mr 56000 induced after infection of Escherichia coli cells with bacteriophage T4, probably the ATPase dependent on gene dda of the phage, was isolated. Studies on the enzyme show that in the presence of ATP and M2+ ions it is capable of dissociating partially double-stranded fd bacteriophage DNA into the single strands and that some 3000 enzyme copies are required to unwind the 6400-nucleotides-long DNA. Unwinding is inhibited by reducing the length of the single-stranded portion of DNA to two nucleotides. In addition it can be inhibited by sulfhydryl reagents which block the ATPase or by trapping free enzyme molecules in the assay system. The results suggest that unwinding is initiated near the single-stranded portion of the DNA and is driven by the ATPase. It further appears that the enzyme unwinds by adsorbing to the DNA. Affinity of the enzyme for double-standed DNA is not detectable by DNA binding assay.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D004265	DNA Helicases	Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition, DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate DNA strands.	ATP-Dependent DNA Helicase,DNA Helicase,DNA Unwinding Protein,DNA Unwinding Proteins,ATP-Dependent DNA Helicases,DNA Helicase A,DNA Helicase E,DNA Helicase II,DNA Helicase III,ATP Dependent DNA Helicase,ATP Dependent DNA Helicases,DNA Helicase, ATP-Dependent,DNA Helicases, ATP-Dependent,Helicase, ATP-Dependent DNA,Helicase, DNA,Helicases, ATP-Dependent DNA,Helicases, DNA,Protein, DNA Unwinding,Unwinding Protein, DNA,Unwinding Proteins, DNA
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
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
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine