Biomaterial Database

DNA polymerase I-mediated ultraviolet repair synthesis in toluene-treated Escherichia coli. 1978

J W Dorson, and R E Moses

DNA synthesis after ultraviolet irradiation is low in wild type toluene-treated cells. The level of repair incorporation is greater in strains deficient in DNA polymerase I. The low level of repair synthesis is attributable to the concerted action of DNA polymerase I and polynucleotide ligase. Repair synthesis is stimulated by blocking ligase activity with the addition of nicotinamide mononucleotide (NMN) or the use of a ligase temperature-sensitive mutant. NMN stimulation is specific for DNA polymerase I-mediated repair synthesis, as it is absent in isogenic strains deficient in the polymerase function or the 5' leads to 3' exonuclease function associated with DNA polymerase I. DNA synthesis that is stimulated by NMN is proportional to the ultraviolet exposure at low doses, nonconservative in nature, and is dependent on the uvrA gene product but is independent of the recA gene product. These criteria place this synthesis in the excision repair pathway. The NMN-stimulated repair synthesis requires ATP and is N-ethylmaleimide-resistant. The use of NMN provides a direct means for evaluating the involvement of DNA polymerase I in excision repair.

UI	MeSH Term	Description	Entries
D009537	Nicotinamide Mononucleotide	3-Carbamoyl-1-beta-D-ribofuranosyl pyridinium hydroxide-5'phosphate, inner salt. A nucleotide in which the nitrogenous base, nicotinamide, is in beta-N-glycosidic linkage with the C-1 position of D-ribose. Synonyms: Nicotinamide Ribonucleotide; NMN.	Mononucleotide, Nicotinamide
D011118	Polynucleotide Ligases	Catalyze the joining of preformed ribonucleotides or deoxyribonucleotides in phosphodiester linkage during genetic processes. EC 6.5.1.	Polynucleotide Synthetases,Ligases, Polynucleotide,Synthetases, Polynucleotide
D011740	Pyrimidine Dimers	Dimers found in DNA chains damaged by ULTRAVIOLET RAYS. They consist of two adjacent PYRIMIDINE NUCLEOTIDES, usually THYMINE nucleotides, in which the pyrimidine residues are covalently joined by a cyclobutane ring. These dimers block DNA REPLICATION.	Cyclobutane Pyrimidine Dimer,Cyclobutane-Pyrimidine Dimer,Cytosine-Thymine Dimer,Pyrimidine Dimer,Thymine Dimer,Thymine Dimers,Cyclobutane-Pyrimidine Dimers,Cytosine-Thymine Dimers,Thymine-Cyclobutane Dimer,Thymine-Thymine Cyclobutane Dimer,Cyclobutane Dimer, Thymine-Thymine,Cyclobutane Dimers, Thymine-Thymine,Cyclobutane Pyrimidine Dimers,Cytosine Thymine Dimer,Cytosine Thymine Dimers,Pyrimidine Dimer, Cyclobutane,Pyrimidine Dimers, Cyclobutane,Thymine Cyclobutane Dimer,Thymine Thymine Cyclobutane Dimer,Thymine-Cyclobutane Dimers,Thymine-Thymine Cyclobutane Dimers
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
D004259	DNA-Directed DNA Polymerase	DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair.	DNA Polymerase,DNA Polymerases,DNA-Dependent DNA Polymerases,DNA Polymerase N3,DNA Dependent DNA Polymerases,DNA Directed DNA Polymerase,DNA Polymerase, DNA-Directed,DNA Polymerases, DNA-Dependent,Polymerase N3, DNA,Polymerase, DNA,Polymerase, DNA-Directed DNA,Polymerases, DNA,Polymerases, DNA-Dependent DNA
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
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
D005092	Exonucleases	Enzymes that catalyze the release of mononucleotides by the hydrolysis of the terminal bond of deoxyribonucleotide or ribonucleotide chains.	Exonuclease,3'-5'-Exonuclease,3'-5'-Exonucleases,5'-3'-Exonuclease,5'-3'-Exonucleases,3' 5' Exonuclease,3' 5' Exonucleases,5' 3' Exonuclease,5' 3' Exonucleases
D014050	Toluene	A widely used industrial solvent.