@article {1167,
	title = {Initiation of mitochondrial DNA replication by transcription and R-loop processing.},
	journal = {The Journal of Biological Chemistry},
	volume = {273},
	year = {1998},
	month = {1998 Nov 13},
	pages = {30614-21},
	abstract = {<p>The mitochondrial genome of eukaryotic cells is maintained by a mechanism distinct from that employed in the nucleus. Mitochondrial DNA replication at the leading-strand origin is coupled to transcription through the formation of an RNA-DNA hybrid known as an R-loop. In vivo and in vitro evidence has implicated an RNA processing enzyme, RNase MRP, in primer maturation. In our investigation of mammalian RNase MRP, we have analyzed its specific endoribonuclease activity on model R-loops. We demonstrate here that human RNase MRP cleaves this distinctly configured substrate at virtually all of the major DNA replication sites previously mapped in vivo. We further show that the processed RNA products remain stably base-paired to the template DNA strand and are functional for initiating DNA synthesis on a closed circular plasmid. Thus, in vitro initiation of leading-strand mtDNA synthesis requires only the actions of RNA polymerase and RNase MRP for the generation of replication primers.</p>
},
	keywords = {Base Sequence, Catalytic Domain, Cell Line, Circular, DNA, DNA Replication, Endoribonucleases, Genetic, Humans, Mitochondrial, Molecular Sequence Data, Nucleic Acid Conformation, Ribonucleoproteins, RNA, Transcription},
	issn = {0021-9258},
	doi = {10.1101/gad.1352105},
	author = {Lee, D Y and Clayton, D A}
}
@article {1187,
	title = {RNase MRP correctly cleaves a novel R loop at the mitochondrial DNA leading-strand origin of replication.},
	journal = {Genes \& Development},
	volume = {11},
	year = {1997},
	month = {1997 Mar},
	pages = {582-92},
	abstract = {<p>The precursor primer RNA for mammalian mitochondrial DNA leading-strand replication remains as a persistent R loop formed during transcription through the mitochondrial DNA control region. We have examined model R loops, which exist in a novel and physiologically accurate preprimer conformation, as potential substrates for mammalian RNase mitochondrial RNA processing (MRP). Mouse RNase MRP accurately cleaves an R loop containing the mouse mitochondrial DNA origin. The multiple cleavage sites on the R-loop substrate match the priming sites observed in vivo, suggesting that RNase MRP alone is capable of generating virtually all of the leading-strand replication primers.</p>
},
	issn = {0890-9369},
	author = {Clayton, D A and Lee, D Y}
}
