The linear mitochondrial plasmid pClK1 of the phytopathogenic fungus Claviceps purpurea may code for a DNA polymerase and an RNA polymerase

1989 ◽  
Vol 217 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Birgitt Oeser ◽  
Paul Tudzynski
Keyword(s):  
Rna Polymerase ◽  
Dna Polymerase ◽  
Phytopathogenic Fungus ◽  
Claviceps Purpurea ◽  
Mitochondrial Plasmid ◽  
Linear Mitochondrial Plasmid

Oligo(A)-stimulated Tetrahymena rDNA synthesis in vitro

1981 ◽  
Vol 59 (6) ◽  
pp. 396-403 ◽  
Author(s):  
Peter R. Ganz ◽  
Gyorgy B. Kiss ◽  
Ronald E. Pearlman
Keyword(s):  
Rna Polymerase ◽  
Dna Synthesis ◽  
Dna Polymerase ◽  
Ribosomal Rna ◽  
Replication Proteins ◽  
General Applicability ◽  
In Vitro Synthesis ◽  
Restriction Fragments ◽  
Double Stranded Dna

The synthesis of Tetrahymena rDNA has been examined using purified DNA polymerase and partially purified preparations of homologous replication enzymes (fraction IV). DNA synthesis with purified DNA polymerase alone was less than that with fraction IV enzymes. This suggested that there were additional factors in fraction IV other than DNA polymerase which contributed to or enhanced rDNA synthesis in vitro. Neither hybridization of rDNA with Tetrahymena ribosomal RNA nor preincubation of rDNA with homologous or heterologous RNA polymerase served to stimulate in vitro synthesis by fraction IV enzymes. However, when rDNA was hybridized with oligoriboadenylate, DNA synthesis using fraction IV was stimulated approximately 4- to 4.5-fold over 150 min of incubation, relative to a similarly treated but unhybridized rDNA control. Using oligoriboadenylate-hybridized EcoR1 and HindIII restriction fragments of rDNA to localize the synthesis most of the in vitro synthesis occurred within a 2.4 × 106 Mr fragment encompassing the centre of the rDNA molecule. The approach of hybridizing a synthetic homooligoribonucleotide primer to double-stranded DNA should prove to be of general applicability in designing similar template–primers in other systems for the purpose of isolating replication proteins.

Linear plasmids that integrate into mitochondrial DNA in Neurospora

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 155-159 ◽  
Author(s):  
H. Bertrand ◽  
A. J. F. Griffiths
Keyword(s):  
Mitochondrial Dna ◽  
Rna Polymerase ◽  
Dna Polymerase ◽  
Inverted Repeats ◽  
Insertion Sequences ◽  
Long Terminal Repeats ◽  
Linear Plasmids ◽  
Mt Dna ◽  
Common Features ◽  
Mitochondrial Chromosome

In some field isolates of Neurospora from Hawaii and India, senescence is induced by integration of linear DNA plasmids, kalilo and maranhar, respectively, into mitochondrial (mt) DNA. Although the two plasmids show little homology at the DNA level, both have inverted long terminal repeats, and each potentially encodes a DNA polymerase and a RNA polymerase. Both plasmids generate very long inverted repeats of mtDNA at their ends upon integration into mitochondrial chromosomes. Hence, they appear to integrate by a mechanism that involves pairing of both ends of the plasmid with short stretches of homologous nucleotide sequences in mtDNA. This recombinogenic association apparently generates an origin for an unscheduled round of replication of mtDNA. In the process, the resulting two copies of the mitochondrial chromosome are joined to opposite ends of the plasmid. A model for the senescence-associated accumulation of mtDNAs with plasmid insertion sequences is proposed on the basis of common features that characterize senescence in a variety of filamentous fungi.Key words: Neurospora, senescence, plasmids, mitochondria.

scholarly journals DNA polymerase ε associates with the elongating form of RNA polymerase II and nascent transcripts

FEBS Journal ◽  
2006 ◽  
Vol 273 (24) ◽  
pp. 5535-5549 ◽  
Author(s):  
Anna K. Rytkönen ◽  
Tomi Hillukkala ◽  
Markku Vaara ◽  
Miiko Sokka ◽  
Maarit Jokela ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Dna Polymerase ◽  
Nascent Transcripts
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