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A study was conducted that compared wt human PCNA with mutant PCNA expressed from a human PCNA cDNA clonebearing a single nucleotide point mutation leading to the single amino acid replacement of lysine for glutamate at position 85 (E85K hPCNA). It concluded that human PCNA, either mutated to contain lysine (K) at position 85 or bearing similar primary mutations, would promote more secondary mutagenesis in cells and/or tissues where PCNA is normally expressed at low levels relative to pol delta.

Research has been conducted on acrolien, a member of the alpha, beta-unsaturated aldehyde family. The role of alpha-OH-1,N (super)2 ?propanodeoxyguanosine adduct in the genotoxicity of this acrolein has been investigated via comparison of alpha-OH-1,N (super)2 ?propanodeoxyguanosine, gamma-OH-1,N (super)2 ?propanodeoxyguanosine and propanodeoxyguanosine by in vitro primer extension studies and in human cells and the details are reported.

Results show that interaction between 8-oxodGTP and aspergine 279 at the DNA polymerase site probably alters conformation of the 8-oxodGTP resulting in its misincorporation by the polymerase.

Primer extension reactions were conducted using the exo- Klenow fragment of NA polymerase I (KF exo-) to address the long-range effects of DNA adducts on DNA polymerase activity. Four different templates containing 7,8-dihydro-8-oxoguanine, dG-C8-aminofluorene, dG--C8-(acetylamino)fluorene and the model abasic site tetrahydrofuran were utilized in the study. Kinetic parameters of nucleotide insertion were established in the absence of proofreading at positions proximal and distal to template lesion.

The epsilon subunit of deoxyribonucleic acid (DNA) polymerase (pol) III was analyzed to determine the mechanisms of DNA replication fidelity and exonucleocytic proofreading without DNA polymerase. The accuracy of DNA proofreading is dependent on exonucleocytic proofreading during the replication process. Furthermore, exonuclease activity of the 3'-5' epsilon subunit of pol III was detected in the integral domain of the polymerase polypeptide.

Complex formation among mammalian DNA polymerase (pol) delta, proliferating cell nuclear antigen (PCNA) and synthetic oligonucleotide template-primers was quantified to elucidate the possible function of PCNA in DNA replication and repair. Three different assay systems were used. In all systems, complex detection needed the simultaneous presence of pol delta, PCNA, and template-primer. Findings indicated for the first time direct stabilization of the pol delta-template-primer complex by PCNA.

Residues Ser38 and Cys42 align with the two cysteines of the redox-active disulfides found in glutathione reductase, lipoamide dehydrogenase, mercuric reductase, and trypanothione reductase in the L40C mutation. However,the formation of the Cys40-Cys42 disulfide bond involved a movement of Cys42-SG to achieve a new position 5.9 angstroms from the flavin-C(4a) position, preventing the disulfide bond from linking with the flavin as a redox center.

Describes the minimal kinetic scheme for Epsilon subunit action on single-stranded DNA oligonucleotides and on paired and mispaired oligonucleotides in the major replicative enzyme of Escherichia coli. Steady state kinetics; Inhibition of exonuclease activity by nucleoside monophosphates; Pre-steady state kinetics.

Reports on a study of the mammalian DNA polymerase sigma-proliferating cell nuclear antigen-template-primer complex. Preparation of nucleic acids for binding studies; Direct assays, Polyacrylamide gel electrophoresis-band mobility shift; Agarose gel electrophoresis-band mobility shift; Nitrocellulose filter binding.

Presents a study on the effect of lesions on dexyribonucleic acid (DNA) polymerase synthesis at positions distant from the premier terminus. Methodology used to conduct the study; Information on primer extension reactions; Reference to previous studies pertaining to DNA polymerase; Discussion on the study.