Biomaterial Database

The excision of AP sites by the 3'-5' exonuclease activity of the Klenow fragment of Escherichia coli DNA polymerase I. 1984

V Bailly, and W G Verly

The 3' AP endonucleases (class I) are said to hydrolyze the phosphodiester bond 3' to AP sites yielding 3'-OH and 5'-phosphate ends; on the other hand, the resulting 3' terminal AP site is not removed by the 3'-5' exonuclease activity of the Klenow fragment [1]. We show that AP sites in DNA are easily removed by the 3'-5' exonuclease activity of the Klenow fragment and that they are excised as deoxyribose-5-phosphate. It is suggested that the 3' AP endonucleases are perhaps not the hydrolases they are supposed to be.

UI	MeSH Term	Description	Entries
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D010761	Phosphorus Radioisotopes	Unstable isotopes of phosphorus that decay or disintegrate emitting radiation. P atoms with atomic weights 28-34 except 31 are radioactive phosphorus isotopes.	Radioisotopes, Phosphorus
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004256	DNA Polymerase I	A DNA-dependent DNA polymerase characterized in prokaryotes and may be present in higher organisms. It has both 3'-5' and 5'-3' exonuclease activity, but cannot use native double-stranded DNA as template-primer. It is not inhibited by sulfhydryl reagents and is active in both DNA synthesis and repair.	DNA Polymerase alpha,DNA-Dependent DNA Polymerase I,Klenow Fragment,DNA Pol I,DNA Dependent DNA Polymerase I,Polymerase alpha, DNA
D004706	Endodeoxyribonucleases	A group of enzymes catalyzing the endonucleolytic cleavage of DNA. They include members of EC 3.1.21.-, EC 3.1.22.-, EC 3.1.23.- (DNA RESTRICTION ENZYMES), EC 3.1.24.- (DNA RESTRICTION ENZYMES), and EC 3.1.25.-.
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
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
D043223	Deoxyribonuclease IV (Phage T4-Induced)	An enzyme which catalyzes the endonucleolytic cleavage of phosphodiester bonds at purinic or apyrimidinic sites (AP-sites) to produce 5'-Phosphooligonucleotide end products. The enzyme prefers single-stranded DNA (ssDNA) and was formerly classified as EC 3.1.4.30.	Deoxyriboendonuclease IV,Endonuclease IV,Redoxyendonuclease
D043603	DNA-(Apurinic or Apyrimidinic Site) Lyase	A DNA repair enzyme that catalyses the excision of ribose residues at apurinic and apyrimidinic DNA sites that can result from the action of DNA GLYCOSYLASES. The enzyme catalyzes a beta-elimination reaction in which the C-O-P bond 3' to the apurinic or apyrimidinic site in DNA is broken, leaving a 3'-terminal unsaturated sugar and a product with a terminal 5'-phosphate. This enzyme was previously listed under EC 3.1.25.2.	Apurinic DNA Endonuclease,DNA Lyase (Apurinic or Apyrimidinic),Endodeoxyribonuclease (Apurinic or Apyrimidinic),AP Endonuclease,AP Lyase,Apurine-Apyrimidine Endonuclease,Apurinic Endonuclease,Apurine Apyrimidine Endonuclease,DNA Endonuclease, Apurinic,Endonuclease, AP,Endonuclease, Apurine-Apyrimidine,Endonuclease, Apurinic,Endonuclease, Apurinic DNA
D029968	Escherichia coli Proteins	Proteins obtained from ESCHERICHIA COLI.	E coli Proteins