Biomaterial Database

Exonucleolytic proofreading of leading and lagging strand DNA replication errors. 1991

J D Roberts, and D C Thomas, and T A Kunkel

Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709.

We have asked whether exonucleolytic proofreading occurs during simian virus 40 origin-dependent, bidirectional DNA replication in extracts of human HeLa cells. In addition, we have compared the fidelity of leading and lagging strand DNA synthesis. In a fidelity assay that scores single-base substitution errors that revert a TGA codon in the lacZ alpha gene in an M13mp vector, providing an excess of a single dNTP substrate over the other three dNTP substrates in a replication reaction generates defined, strand-specific errors. Fidelity measurements with two vectors having the origin of replication on opposite sides of the opal codon demonstrate that error rates for two different A.dCTP and T.dGTP mispairs increase when deoxyguanosine monophosphate is added to replication reaction mixtures or when the concentration of deoxynucleoside triphosphates is increased. The data suggest that exonucleolytic proofreading occurs on both strands during bidirectional replication. Measurements using the two simian virus 40 origin-containing vectors suggest that base substitution error rates are similar for replication of the leading and lagging strands.

UI	MeSH Term	Description	Entries
D003854	Deoxyribonucleotides	A purine or pyrimidine base bonded to a DEOXYRIBOSE containing a bond to a phosphate group.	Deoxyribonucleotide
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
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D005090	Exodeoxyribonucleases	A family of enzymes that catalyze the exonucleolytic cleavage of DNA. It includes members of the class EC 3.1.11 that produce 5'-phosphomonoesters as cleavage products.	DNA Exonucleases,Exonucleases, 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
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000952	Antigens, Polyomavirus Transforming	Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.	Polyomavirus Large T Antigens,Polyomavirus Middle T Antigens,Polyomavirus Small T Antigens,Polyomavirus T Proteins,Polyomavirus Transforming Antigens,Polyomavirus Tumor Antigens,SV40 T Antigens,SV40 T Proteins,Simian Sarcoma Virus Proteins,Polyomaviruses Large T Proteins,Polyomaviruses Middle T Proteins,Polyomaviruses Small T Proteins,Antigens, Polyomavirus Tumor,Antigens, SV40 T,Proteins, Polyomavirus T,Proteins, SV40 T,T Antigens, SV40,T Proteins, Polyomavirus,T Proteins, SV40,Transforming Antigens, Polyomavirus,Tumor Antigens, Polyomavirus
D001616	beta-Galactosidase	A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.	Lactases,Dairyaid,Lactaid,Lactogest,Lactrase,beta-D-Galactosidase,beta-Galactosidase A1,beta-Galactosidase A2,beta-Galactosidase A3,beta-Galactosidases,lac Z Protein,Protein, lac Z,beta D Galactosidase,beta Galactosidase,beta Galactosidase A1,beta Galactosidase A2,beta Galactosidase A3,beta Galactosidases
D013698	Templates, Genetic	Macromolecular molds for the synthesis of complementary macromolecules, as in DNA REPLICATION; GENETIC TRANSCRIPTION of DNA to RNA, and GENETIC TRANSLATION of RNA into POLYPEPTIDES.	Genetic Template,Genetic Templates,Template, Genetic