title: A 70-kDa chloroplast DNA polymerase from pea ( Pisum sativum) that shows high processivity and displays moderate fidelity.
abstract: A 70-kDa chloroplast (ct) DNA polymerase from pea has been purified to apparent homogeneity. The ct DNA polymerase was insensitive to dideoxynucleotides (d(2) NTP) but showed high sensitivity to phosphonoacetic acid. The enzyme lacked any detectable 5'-->3' exonuclease activity but showed 3'-->5' exonuclease activity. The polymerase displayed high processivity (3 kb) and moderate fidelity, which may be sufficient for the faithful replication of the 140-kb pea ct genome. A 43-kDa accessory protein increased the polymerization rate but did not affect the rate of mis-incorporation in vitro, thus indicating that the domains for polymerisation and proof reading may be spatially separate.
authors.affiliation: Plant Molecular Biology, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
authors.forename: A
authors.initials: A
authors.lastname: Gaikwad
authors.forename: D V
authors.initials: DV
authors.lastname: Hop
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Mukherjee
mesh_terms: D001483:Base Sequence; D004261:DNA Replication; D018744:DNA, Plant; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000378:metabolism; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors; D018532:Pisum sativum / Q000201:enzymology* / Q000235:genetics
chemical_list: D018744:DNA, Plant; D004791:Enzyme Inhibitors; D019384:Nucleic Acid Synthesis Inhibitors; D004259:DNA-Directed DNA Polymerase; D005090:Exodeoxyribonucleases; D043211:Exodeoxyribonuclease V