Nucleic Acids Research, 1983, Vol. 11, No. 23 8269-8282
© 1983
MOLECULAR BIOLOGY |
Initiation of transcription of the yeast mitochondrial gene coding for ATPase subunit 9
*Departments of Medicine, Biochemistry and Biology, University of Chicago Chicago, IL 60637, USA +Section for Molecular Biology, Laboratory of Biochemistry, University of Amsterdam Kruislaan 318, 1098 SM Amsterdam, The Netherlands
Received September 6, 1983. Revised October 19, 1983. Accepted October 19, 1983.
We have determined transcriptional initiation sites for the ATPase subunit 9 gene on the yeast mitochondrial genome. Using S1 nuclease mapping, in vitro capping of primary transcripts with GTP and guanylyl transferase, and in vitro transcription analysis with purified mitochondrial RNA polymerase, we find the major site of transcriptional initiation to be at a point 630 nucleotides upstream of the coding region for the gene. In addition, we find much lower levels of initiation at a second site 78 nucleotides downstream of the first. Both initiation sites occur at the same position within a nonanucleotide sequence which we have previously found associated with initiation of rRNA synthesis. This work further supports the notion that this nonanucleotide sequence 1s an integral component of mitochondrial promoters and indicates that the same RNA polymerase is used for transcription of both mRNA and rRNA in yeast mitochondria.