Title: DNA polymerase B from wheat embryos: A plant δ-like DNA polymerase
Abstract: Studies in eucaryotic cells (mainly animals and yeast) indicate that at least two DNA polymerases are involved in DNA replication at the level of the replication fork: DNA polymerase α, which is associated with DNA primase, is involved in the replication of the lagging strand; DNA polymerase δ, associated with an exonuclease activity, synthesizes the forward continuous DNA strand. Much less information exists concerning plant systems. Previous work from this laboratory provided preliminary evidence of an association between DNA polymerase B from wheat embryo and an exonucleolytic activity. In this paper, we present additional data on the biochemical properties of DNA polymerase B. An improved purification procedure described in this article has been developed. During all the purification steps the nuclease activity was associated with DNA polymerase activity. A biochemical study of this enzyme activity shows that it is an exonuclease which hydrolyses DNA in the 3′ to 5′ direction. Moreover, this exonuclease confers a proofreading function to DNA polymerase B. Comparison of DNA polymerase B properties (template specificity, sensitivity to DNA replication inhibitors like aphidicolin and butyl-phenyl dGTP, copurification of DNA polymerase and exonuclease activities) with those of animal DNA polymerase δ indicates that these enzymes share many common features. To our knowledge, this is the first report of DNA polymerase δ in higher plants.
Publication Year: 1991
Publication Date: 1991-05-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 42
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