Biomaterial Database

The role of DNA polymerases alpha, beta and gamma in nuclear DNA synthesis. 1979

E Wist

The effects of the inhibitors 2'3' dideoxythymidine triphosphate (ddTTP) and 1-beta-D-arabinofuranosyl cytosine triphosphate (araCTP) on DNA synthesis in isolated S-phase HeLa S3 nuclei have been examined. These effects are compared with the effects of the same inhibitors in partially purified preparations of DNA polymerases alpha and beta. The effect of ddTTP on partially purified DNA polymerase gamma was also tested. DNA polymerases beta and gamma were very sensitive to ddTTP whereas DNA polymerase alpha and DNA synthesis in isolated nuclei were quite resistant. The synthesis and subsequent ligation of primary DNA pieces ('Okazaki fragments') were not affected by the presence of this inhibitor. DNA synthesis in isolated nuclei and DNA polymerase alpha activity were very sensitive to araCTP whereas DNA polymerase beta was almost totally resistant to the inhibitor. The results indicate a major role for DNA polymerase alpha in DNA replication.

UI	MeSH Term	Description	Entries
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D003854	Deoxyribonucleotides	A purine or pyrimidine base bonded to a DEOXYRIBOSE containing a bond to a phosphate group.	Deoxyribonucleotide
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
D004257	DNA Polymerase II	A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms. It may be present in higher organisms and has an intrinsic molecular activity only 5% of that of DNA Polymerase I. This polymerase has 3'-5' exonuclease activity, is effective only on duplex DNA with gaps or single-strand ends of less than 100 nucleotides as template, and is inhibited by sulfhydryl reagents.	DNA Polymerase epsilon,DNA-Dependent DNA Polymerase II,DNA Pol II,DNA Dependent DNA Polymerase II
D004258	DNA Polymerase III	A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms but may be present in higher organisms. Use also for a more complex form of DNA polymerase III designated as DNA polymerase III* or pol III* which is 15 times more active biologically than DNA polymerase I in the synthesis of DNA. This polymerase has both 3'-5' and 5'-3' exonuclease activities, is inhibited by sulfhydryl reagents, and has the same template-primer dependence as pol II.	DNA Polymerase delta,DNA-Dependent DNA Polymerase III,DNA Pol III,DNA Dependent DNA Polymerase III,Polymerase III, DNA,Polymerase delta, 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
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D001085	Arabinofuranosylcytosine Triphosphate	A triphosphate nucleotide analog which is the biologically active form of CYTARABINE. It inhibits nuclear DNA synthesis.	Ara-CTP,Arabinosylcytosine Triphosphate,Cytarabine Triphosphate,Cytosine Arabinoside Triphosphate,Ara CTP,Triphosphate, Arabinofuranosylcytosine,Triphosphate, Arabinosylcytosine,Triphosphate, Cytarabine,Triphosphate, Cytosine Arabinoside
D013942	Thymine Nucleotides	Phosphate esters of THYMIDINE in N-glycosidic linkage with ribose or deoxyribose, as occurs in nucleic acids. (From Dorland, 28th ed, p1154)	Thymidine Phosphates,Nucleotides, Thymine,Phosphates, Thymidine