Biomaterial Database

DNA repair in Escherichia coli mutants deficient in DNA polymerases I, II and-or 3. 1974

R C Tait, and A L Harris, and D W Smith

E. coli mutants deficient in DNA polymerase I, in DNA polymerases I and II, or in DNA polymerase III, can efficiently and completely execute excision repair and post-replication repair of UV-damaged DNA at 43 degrees when assayed by alkaline sucrose gradients. Repair by cells deficient in polymerase I and in polymerases I and II is inhibited by 1-beta-D-arabinofuranosylcytosine at 43 degrees , whereas that by cells deficient in polymerase III is insensitive to the inhibitor. When both DNA polymerases I and III are deficient, both excision repair and post-replication repair are greatly reduced at 43 degrees , and the residual repair capability is inhibited by 1-beta-D-arabinofuranosylcytosine. Very little dark repair is observed in cells deficient in DNA polymerases I, II, and III, and the DNA is extensively degraded. These results suggest that either DNA polymerase I or DNA polymerase III is required for complete and efficient repair, and that when both DNA polymerases I and III are deficient, DNA polymerase II mediates a limited, incomplete dark repair of UV-damaged DNA. DNA polymerases I and III thus appear to be important enzymes in both DNA replication and DNA dark repair.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D011830	Radiation Effects	The effects of ionizing and nonionizing radiation upon living organisms, organs and tissues, and their constituents, and upon physiologic processes. It includes the effect of irradiation on food, drugs, and chemicals.	Effects, Radiation,Effect, Radiation,Radiation Effect
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D003561	Cytarabine	A pyrimidine nucleoside analog that is used mainly in the treatment of leukemia, especially acute non-lymphoblastic leukemia. Cytarabine is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. Its actions are specific for the S phase of the cell cycle. It also has antiviral and immunosuppressant properties. (From Martindale, The Extra Pharmacopoeia, 30th ed, p472)	Ara-C,Arabinofuranosylcytosine,Arabinosylcytosine,Cytosine Arabinoside,Aracytidine,Aracytine,Cytarabine Hydrochloride,Cytonal,Cytosar,Cytosar-U,beta-Ara C,Ara C,Arabinoside, Cytosine,Cytosar U,beta Ara C
D003864	Depression, Chemical	The decrease in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.	Chemical Depression,Chemical Depressions,Depressions, Chemical
D004254	DNA Nucleotidyltransferases	Enzymes that catalyze the incorporation of deoxyribonucleotides into a chain of DNA. EC 2.7.7.-.	Nucleotidyltransferases, 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