Identification and Characterization of Human DNA Polymerase β2, a DNA Polymerase β-Related Enzyme
| Autor: | Momoki Hirai, Akio Matsukage, Yuji Nimura, Akihiro Yasui, Kyoji Ikeda, Kei-ichi Nagasawa, Kenzo Kitamura, Makoto Nakanishi |
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| Rok vydání: | 2000 |
| Předmět: |
Insecta
DNA polymerase Recombinant Fusion Proteins viruses DNA polymerase II Amino Acid Motifs Green Fluorescent Proteins Immunoblotting Molecular Sequence Data Polymerase Chain Reaction Biochemistry DNA polymerase delta Cell Line DNA Nucleotidylexotransferase Animals Humans Tissue Distribution Amino Acid Sequence Cloning Molecular Molecular Biology DNA Polymerase beta In Situ Hybridization Fluorescence Polymerase Cell Nucleus Binding Sites Sequence Homology Amino Acid biology DNA replication Cell Biology Processivity Blotting Northern Molecular biology DNA polymerase lambda Protein Structure Tertiary Luminescent Proteins biology.protein DNA polymerase mu HeLa Cells |
| Zdroj: | Journal of Biological Chemistry. 275:31233-31238 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m004263200 |
| Popis: | The BRCA1 COOH terminus (BRCT) motif is present in many nuclear proteins that contribute to cell cycle regulation or DNA repair. Polymerase chain reaction-based screening with degenerate primers targeted to the BRCT motif resulted in the isolation of a human cDNA for a previously unidentified DNA polymerase (designated DNA polymerase beta2) that is closely related to DNA polymerase beta (Pol beta). The predicted Pol beta2 protein contains a BRCT motif in its NH(2)-terminal region; its COOH-terminal region exhibits 33% sequence identity to a corresponding region of human Pol beta. The Pol beta2 gene is expressed in a tissue-specific manner, with transcripts being most abundant in testis. A fusion construct comprising Pol beta2 and green fluorescent protein exhibited a predominantly nuclear localization in transfected HeLa cells. Recombinant human Pol beta2 from insect cells exhibited substantial DNA polymerase activity, but it did not possess terminal deoxyribonucleotidyl transferase activity. A truncated Pol beta2 mutant lacking the BRCT motif retained substantial DNA polymerase activity, whereas a mutant Pol beta2 with two alanine point mutations within the DNA polymerase active site did not. These results indicate that Pol beta2 is a Pol beta-related DNA polymerase with a BRCT motif that is dispensable for its polymerase activity. |
| Databáze: | OpenAIRE |
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