Archaebacterial DNA polymerases tightly bind uracil-containing DNA.
We show that archaebacterial DNA polymerases are strongly inhibited by the presence of small amounts of uracil-containing DNA. Inhibition appears to be competitive, with the DNA polymerase exhibiting approximately 6500-fold greater affinity for binding the inhibitor than a DNase I-activated DNA substrate. All six archaebacterial DNA polymerases tested were inhibited, while no eubacterial, eukaryotic, or bacteriophage enzymes showed this effect. Only a small inhibition resulted when uracil was present as the deoxynucleoside triphosphate, dUTP. The rate of DNA synthesis was reduced by approximately 40% when dUTP was used in place of dTTP for archaebacterial DNA polymerases. Furthermore, an incorporated dUMP served as a productive 3'-primer terminus for subsequent elongation. In contrast, the presence of an oligonucleotide containing as little as a single dUrd residue was extremely inhibitory to DNA polymerase activity on other primer-template DNA.
Lasken
R S
RS
Life Technologies, Inc., Gaithersburg, Maryland 20884-9980, USA.
Schuster
D M
DM
Rashtchian
A
A
D001105:Archaea / Q000201:enzymology*; D001482:Base Composition; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D003856:Deoxyuracil Nucleotides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors; D009841:Oligonucleotides / Q000494:pharmacology; D011485:Protein Binding; D013942:Thymine Nucleotides / Q000378:metabolism; D014498:Uracil / Q000378:metabolism*
D004269:DNA, Bacterial; D003856:Deoxyuracil Nucleotides; D019384:Nucleic Acid Synthesis Inhibitors; D009841:Oligonucleotides; D013942:Thymine Nucleotides; D014498:Uracil; C007267:2'-deoxyuridylic acid; D004259:DNA-Directed DNA Polymerase; C024157:thymidine 5'-triphosphate