caa a22 4500 465757782 CHVBK 20180323111852.0 cr unu---uuuuu 170327e19901101xx s 000 0 eng 10.1007/BF00318218 doi (NATIONALLICENCE)springer-10.1007/BF00318218 Analysis of large deletions in the Mauriceville and Varkud mitochondrial plasmids of Neurospora [Elektronische Daten] [Robert Akins, Alan Lambowitz] Summary: The Mauriceville and Varkud mitochondrial plasmids are closely related, closed-circular DNAs (3.6 and 3.7 kb, respectively) that have characteristics of mtDNA introns and retroid elements. Both plasmids contain a 710 amino acid open reading frame (ORF) that encodes an 81 kDa protein having reverse transcriptase activity. Here, we analyzed two mutant plasmids, V5-36 and M3-24, that have undergone relatively large deletions (approximately 0.35 and 0.5 kb, respectively). Both deletions occur downstream of the long ORF in a noncoding region of the plasmids that contains a direct repeat of 160 bp and a cluster of five PstI-palindromes, a repetitive sequence element in Neurospora mtDNA. In V5-36, the deletion end points are at the bases of two hairpin structures that are centered around PstI-palindromes and flank the deleted region. In M3-24, the deletion junction contains an extra T-residue that is not encoded in the plasmid. In both plasmids, the deletion end points do not correspond to homologous or directly repeated sequences of more than one nucleotide, whose pairing could account for the deletion junction. The characteristics of the deletion end points can be accounted for either by illegitimate recombination, possibly following double strand breaks at cruciform structures, or by interruption of reverse transcription followed by reinitiation downstream. The finding that the deletions encompass the 160 bp direct repeat and all five PstI-palindromes indicates that neither are required for propagation of the plasmids and supports the hypothesis that PstI-palindromes are selfish DNA elements that inserted into a nonessential region of the plasmid. Springer-Verlag, 1990 Mitochondrial plasmid nationallicence Reverse transcription nationallicence Illegitimate recombination nationallicence Cruciform structure nationallicence Akins Robert Department of Molecular Genetics and Biochemistry and the Biotechnology Center, The Ohio State University, 484 W. 12th Avenue, 43210, Columbus, OH, USA aut Lambowitz Alan Department of Molecular Genetics and Biochemistry and the Biotechnology Center, The Ohio State University, 484 W. 12th Avenue, 43210, Columbus, OH, USA aut Current Genetics Springer-Verlag 18/4(1990-11-01), 365-369 0172-8083 18:4<365 1990 18 294 https://doi.org/10.1007/BF00318218 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00318218 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Akins Robert Department of Molecular Genetics and Biochemistry and the Biotechnology Center, The Ohio State University, 484 W. 12th Avenue, 43210, Columbus, OH, USA aut NATIONALLICENCE 700 1- Lambowitz Alan Department of Molecular Genetics and Biochemistry and the Biotechnology Center, The Ohio State University, 484 W. 12th Avenue, 43210, Columbus, OH, USA aut NATIONALLICENCE 773 0- Current Genetics Springer-Verlag 18/4(1990-11-01), 365-369 0172-8083 18:4<365 1990 18 294 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer