Studies on a DNA polymeraseγ‐like enzyme from wheat embryos

Mammalian Proliferating Cell Nuclear Antigen Stimulates the Processivity of Two Wheat Embryo DNA Polymerases

“…In our first report on this enzyme, we compared DNA polymerase A to animal DNA polymerase y in terms of the efficient recognition of the synthetic template-primer poly(rA)-oligo(dT), stimulation by KCI, and resistance to aphidicolin (Tarrago-Litvak et al, 1975). Nevertheless, DNA polymerase A seems different from the wheat mitochondrial DNA polymerase (Christophe et al, 1981;Ricard et al, 1983) and the chloroplast DNA polymerase with regard to template specificity (P. Laquel, unpublished results).…”

“…Four extramitochondrial DNA polymerases from wheat germ have previously been characterized (Litvak and Castroviejo, 1987; Table I). Wheat DNA polymerase A has some puzzling properties (Tarrago-Litvak et al, 1975;Laquel et al, 1990b): this polymerase is able to copy natural and synthetic RNA templates and thus shares some properties with the retroviral reverse transcriptase (Laquel et al, 1990b). On the other hand, as in the case of animal DNA polymerase a, DNA polymerase A copurifies with wheat DNA primase, the enzyme involved in the synthesis of short RNA primers of the lagging DNA strand (Graveline et al, 1984;Laquel et al, 1990a).…”

History of DNA Polymerases

“…In 1975 they purified and partially characterized three cytoplasmic DNA pols (A, B and C) from ungerminated wheat embryos and another DNA pol from purified mitochondria that behaves like DNA pol B. 102 Considering the possibility that cytoplasmic DNA pol B was a release product of broken mitochondria, on the basis of chromatographic separation, template-specificity and enzyme properties, the conclusions emerging from their and others' studies [103][104][105][106][107] were that: 1) plants might contain two high MW DNA pols; 2) such enzymes possessed associated exonuclease activities like those of bacterial DNA pols, and 3) that no low MW DNA pol analogous to animal DNA pol b was found in plant cells.…”

Characterization of DNA Polymerases in an Uninfected and Virus PBCV-1-Infected Green Alga – <i>Chlorella</i> Strain NC64A

“…N-ethylmaleimide (10 m M) [14] also in hibited each of the DNA polymerases to some extent and was the best inhibitor for differentiating between the soluble and par ticulate polymerases. With the exception of the Sio DNA polymerase from uninfected cells, none of the enzymes was inhibited sig nificantly by 20 \iM 2',3'-dideoxythymidine-5'-triphosphate (ddTTP) [13].…”

“…Aphidicolin (36 pM) [12] partially inhibited the S|0 DNA polymerase in uninfected cells and the DNA-independent Pl0 DNA poly merase in infected cells. Ethidium bromide (20 pA/) [13] inhibited each of the DNA poly merases in uninfected and infected Chlorella cells. N-ethylmaleimide (10 m M) [14] also in hibited each of the DNA polymerases to some extent and was the best inhibitor for differentiating between the soluble and par ticulate polymerases.…”