Palindrome-hairpin linear plasmids possessing only a part of the ORF1 gene of the yeast killer plasmid pGKL1

1988 ◽  
Vol 215 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Kunio Kitada ◽  
Norio Gunge
1982 ◽  
Vol 2 (4) ◽  
pp. 346-354
Author(s):  
H Bussey ◽  
W Sacks ◽  
D Galley ◽  
D Saville

M double-stranded RNA (MdsRNA) plasmid mutants were obtained by mutagenesis and screening of a diploid killer culture partially heat cured of the plasmid, so that a high proportion of the cells could be expected to have only on M plasmid. Mutants with neutral (nonkiller [K-], immune [R+]) or suicide (killer [K+], sensitive [R-] phenotypes were examined. All mutants became K- R- sensitives on heat curing of the MdsRNA plasmid, and showed cytoplasmic inheritance by random spore analysis. In some cases, M plasmid mutations were indicated by altered mobility of the MdsRNA by agarose gel electrophoresis or by altered size of in vitro translation products from denatured dsRNA. Neutral mutants were of two types: nonsecretors of the toxin protein or secretors of an inactive toxin. Of three neutral nonsecretors examined, one (NLP-1), probably a nonsense mutation, made a smaller protoxin precursor in vitro and in vivo, and two made full-size protoxin molecules. The in vivo protoxin of 43,000 molecular weight was unstable in the wild type and kinetically showed a precursor-product relationship to the processed, secreted 11,000-molecular-weight toxin. In one nonsecretor (N1), the protoxin appeared more stable in a pulse-chase experiment, and could be altered in a recognition site required for protein processing.


1987 ◽  
Vol 15 (21) ◽  
pp. 9088-9088 ◽  
Author(s):  
Guhung Jung ◽  
Mark C. Leavitt ◽  
Junetsu Ito

2018 ◽  
Author(s):  
Michal Sýkora ◽  
Martin Pospíšek ◽  
Josef Novák ◽  
Silvia Mrvová ◽  
Libor Krásný ◽  
...  

ABSTRACTTranscription of extrachromosomal elements such as organelles, viruses, and plasmids is dependent on cellular RNA polymerase (RNAP) or intrinsic RNAP encoded by these elements. The yeastKluyveromyces lactiscontains killer DNA plasmids that bear putative non-canonical RNAP genes. Here, we describe the architecture and evolutionary origin of this transcription machinery. We show that the two RNAP subunits interactin vivo, and this complex interacts with another two plasmid-encoded proteins - the mRNA capping enzyme, and a putative helicase which interacts with plasmid-specific DNA. Further, we identify a promoter element that causes 5’ polyadenylation of plasmid-specific transcriptsviaRNAP slippage during transcription initiation, and structural elements that precede the termination sites. As a result, we present a first model of the yeast killer plasmid transcription initiation and intrinsic termination. Finally, we demonstrate that plasmid RNAP and its promoters display high similarity to poxviral RNAP and promoters of early poxviral genes, respectively.


1982 ◽  
Vol 2 (4) ◽  
pp. 346-354 ◽  
Author(s):  
H Bussey ◽  
W Sacks ◽  
D Galley ◽  
D Saville

M double-stranded RNA (MdsRNA) plasmid mutants were obtained by mutagenesis and screening of a diploid killer culture partially heat cured of the plasmid, so that a high proportion of the cells could be expected to have only on M plasmid. Mutants with neutral (nonkiller [K-], immune [R+]) or suicide (killer [K+], sensitive [R-] phenotypes were examined. All mutants became K- R- sensitives on heat curing of the MdsRNA plasmid, and showed cytoplasmic inheritance by random spore analysis. In some cases, M plasmid mutations were indicated by altered mobility of the MdsRNA by agarose gel electrophoresis or by altered size of in vitro translation products from denatured dsRNA. Neutral mutants were of two types: nonsecretors of the toxin protein or secretors of an inactive toxin. Of three neutral nonsecretors examined, one (NLP-1), probably a nonsense mutation, made a smaller protoxin precursor in vitro and in vivo, and two made full-size protoxin molecules. The in vivo protoxin of 43,000 molecular weight was unstable in the wild type and kinetically showed a precursor-product relationship to the processed, secreted 11,000-molecular-weight toxin. In one nonsecretor (N1), the protoxin appeared more stable in a pulse-chase experiment, and could be altered in a recognition site required for protein processing.


1979 ◽  
Vol 32 (2) ◽  
pp. 692-696 ◽  
Author(s):  
W P Kane ◽  
D F Pietras ◽  
J A Bruenn
Keyword(s):  

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 155-159 ◽  
Author(s):  
H. Bertrand ◽  
A. J. F. Griffiths

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.


2021 ◽  
Author(s):  
Jane Hawkey ◽  
Hugh Cottingham ◽  
Alex Tokolyi ◽  
Ryan R Wick ◽  
Louise M Judd ◽  
...  

Linear plasmids are extrachromosomal DNA that have been found in a small number of bacterial species. To date, the only linear plasmids described in the Enterobacteriaceae family belong to Salmonella, first found in Salmonella Typhi. Here, we describe a collection of 12 isolates of the Klebsiella pneumoniae species complex in which we identified linear plasmids. We used this collection to search public sequence databases and discovered an additional 74 linear plasmid sequences in a variety of Enterobacteriaceae species. Gene content analysis divided these plasmids into five distinct phylogroups, with very few genes shared across more than two phylogroups. The majority of linear plasmid-encoded genes are of unknown function, however each phylogroup carried its own unique toxin-antitoxin system and genes with homology to those encoding the ParAB plasmid stability system. Passage in vitro of the 12 linear plasmid-carrying Klebsiella isolates in our collection (which include representatives of all five phylogroups) indicated that these linear plasmids can be stably maintained, and our data suggest they can transmit between K. pneumoniae strains (including members of globally disseminated multidrug resistant clones) and also between diverse Enterobacteriaceae species. The linear plasmid sequences, and representative isolates harbouring them, are made available as a resource to facilitate future studies on the evolution and function of these novel plasmids.


PLoS Genetics ◽  
2015 ◽  
Vol 11 (5) ◽  
pp. e1005139 ◽  
Author(s):  
Reed B. Wickner ◽  
Herman K. Edskes
Keyword(s):  

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