Mitochondrial DNA polymerase from cauliflower inflorescence.

Fukasawa, Hirosuke; Chou, Mei-Yin

doi:10.1266/jjg.55.441

“…In animals and yeasts, DNA polymerase γ is involved in mitochondrial replication [3,4]. In photosynthetic organisms, purification of DNA polymerases has so far been attempted in chloroplasts [5–11] and mitochondria [6,12–15]. However, in the light of recent genomic data (see next paragraph), all of them were partially purified preparations of partially degraded enzymes.…”

mentioning

confidence: 99%

Purification and characterization of organellar DNA polymerases in the red alga Cyanidioschyzon merolae

Moriyama

¹

,

Terasawa

²

,

Fujiwara

³

et al. 2008

View full text Add to dashboard Cite

DNA polymerase γ, a mitochondrial replication enzyme of yeasts and animals, is not present in photosynthetic eukaryotes. Recently, DNA polymerases with distant homology to bacterial DNA polymerase I were reported in rice, Arabidopsis, and tobacco, and they were localized to both plastids and mitochondria. We call them plant organellar DNA polymerases (POPs). However, POPs have never been purified in the native form from plant tissues. The unicellular thermotrophic red alga Cyanidioschyzon merolae contains two genes encoding proteins related to Escherichia coli DNA polymerase I (PolA and PolB). Phylogenetic analysis revealed that PolB is an ortholog of POPs. Nonphotosynthetic eukaryotes also have POPs, which suggested that POPs have an ancient origin before eukaryotic photosynthesis. PolA is a homolog of bacterial DNA polymerase I and is distinct from POPs. PolB was purified from the C. merolae cells by a series of column chromatography steps. Recombinant protein of PolA was also purified. Sensitivity to inhibitors of DNA synthesis was different in PolA, PolB, and E. coli DNA polymerase I. Immunoblot analysis and targeting studies with green fluorescent protein fusion proteins demonstrated that PolA was localized in the plastids, whereas PolB was present in both plastids and mitochondria. The expression of PolB was regulated by the cell cycle. The available results suggest that PolB is involved in the replication of plastids and mitochondria.

show abstract

“…Only recently, the ,B-like DNA polymerase has been reported in the slime mold Dictyostelium (1) and Physarum polycephalum (14) and in the protozoan Tetrahymena (4). In plants, the ,B-like enzyme has been found in Lilium (13) and cauliflower (3). The production of 13-like DNA polymerase is less than 10%o of the total enzyme in Dictyostelium somatic cells, it is limited to late log phase in Tetrahymena, and it is produced in excess of the a-like enzyme in meiotic cells in cauliflower and Lilium sporocytes.…”

mentioning

confidence: 99%

Meiosis in Coprinus: characterization and activities of two forms of DNA polymerase during meiotic stages.

Sakaguchi¹,

Lu²

1982

View full text Add to dashboard Cite

Two forms of DNA polymerase have been studied in the basidiomycete Coprinus. DNA polymerase from basidiocarp tissues at zygotene-pachytene stage has been purified 3,500-fold and defined as DNA polymerase b by virtue of its insensitivity to N-ethylmaleimide and by its low molecular weight (76,000). This enzyme has optimal activity at pH 7.0 to 7.5, at 200 mM KCI, and at 25C incubation temperature. It can use polycytidylic acid-oligo(dG)12_18 as template primer in addition to homodeoxypolymers. The DNA polymerase a is mainly produced in the exponentially growing mycelium. It is sensitive to N-ethylmaleimide and has a temperature optimum at 35°C. At the premeiotic S phase, activities from both polymerase a and polymerase b are found in cell-free extracts. The b enzyme is the only DNA polymerase produced during meiotic prophase. Its assayable activity exhibits two peaks, one at premeiotic S stage and one at pachytene. It is possible that DNA polymerase b is responsible for pachytene repairs involved in recombination.In recent years, we have been interested in the synchronous meiotic system of Coprinus (8,9a,11) and in particular, the DNA repair synthesis and its relationship to genetic recombination (10). In this connection, it is prudent to examine the activities of DNA polymerases during meiotic and premeiotic stages. Our finding has been most interesting, as this represents the first detailed characterization of meiotic DNA polymerase in the higher basidiomycetes.The presence of several distinct types of DNA-dependent DNA polymerases has been well documented; these include I, II, and III for bacteria (5) and alpha, beta, and gamma for mammalian cells (17). The same information is lacking in the lower eucaryotes, especially the higher fungi. As recently as 1977, the lower eucaryotes were believed not to have DNA polymerase , (2). Only recently, the ,B-like DNA polymerase has been reported in the slime mold Dictyostelium (1) and Physarum polycephalum (14) and in the protozoan Tetrahymena (4). In plants, the ,B-like enzyme has been found in Lilium (13) and cauliflower (3). The production of 13-like DNA polymerase is less than 10%o of the total enzyme in Dictyostelium somatic cells, it is limited to late log phase in Tetrahymena, and it is produced in excess of the a-like enzyme in meiotic cells in cauliflower and Lilium sporocytes. It is possible that the 1-like DNA polymerase has an important physiological function to play in meiotic processes and is therefore primarily produced during meiosis. For the present paper, we took advantage of the synchronous meiotic system of Coprinus cinereus to test this possibility, and we present evidence that the 1-like enzyme (to be called DNA polymerase b) is the only DNA polymerase produced during meiotic prophase in C. cinereus. MATERIALS AND METHODSTerminology. The DNA polymerases of procaryotes are named polymerase I, II, and III, whereas those of mammalian cells are classified as polymerase a, 1, and y. In the higher fungi, a new notation may be in order. We propose for the ...

show abstract

“…Only recently, the ,B-like DNA polymerase has been reported in the slime mold Dictyostelium (1) and Physarum polycephalum (14) and in the protozoan Tetrahymena (4). In plants, the ,B-like enzyme has been found in Lilium (13) and cauliflower (3). The production of 13-like DNA polymerase is less than 10%o of the total enzyme in Dictyostelium somatic cells, it is limited to late log phase in Tetrahymena, and it is produced in excess of the a-like enzyme in meiotic cells in cauliflower and Lilium sporocytes.…”

mentioning

confidence: 99%

Meiosis in Coprinus: Characterization and Activities of Two Forms of DNA Polymerase During Meiotic Stages

Sakaguchi

¹

,

Lu

²

1982

Molecular and Cellular Biology

2

0

1

View full text Add to dashboard Cite

Two forms of DNA polymerase have been studied in the basidiomycete Coprinus. DNA polymerase from basidiocarp tissues at zygotene-pachytene stage has been purified 3,500-fold and defined as DNA polymerase b by virtue of its insensitivity to N-ethylmaleimide and by its low molecular weight (76,000). This enzyme has optimal activity at pH 7.0 to 7.5, at 200 mM KCl, and at 25 degrees C incubation temperature. It can use polycytidylic acid-oligo(dG)12-18 as template primer in addition to homodeoxypolymers. The DNA polymerase a is mainly produced in the exponentially growing mycelium. It is sensitive to N-ethylmaleimide and has a temperature optimum at 35 degrees C. At the premeiotic S phase, activities from both polymerase a and polymerase b are found in cell-free extracts. The b enzyme is the only DNA polymerase produced during meiotic prophase. Its assayable activity exhibits two peaks, one at premeiotic S stage and one at pachytene. It is possible that DNA polymerase b is responsible for pachytene repairs involved in recombination.

show abstract

Mitochondrial DNA polymerase from cauliflower inflorescence.

Cited by 9 publications

References 15 publications

Purification and characterization of organellar DNA polymerases in the red alga Cyanidioschyzon merolae

Purification and characterization of organellar DNA polymerases in the red alga Cyanidioschyzon merolae

Meiosis in Coprinus: characterization and activities of two forms of DNA polymerase during meiotic stages.

Meiosis in Coprinus: Characterization and Activities of Two Forms of DNA Polymerase During Meiotic Stages

Contact Info

Product

Resources

About