Nucleic Acids Research, 1983, Vol. 11, No. 23 8519-8533
© 1983
MOLECULAR BIOLOGY |
Localization and DNA sequence around the initiation site of ribosomal RNA transcription in Physarum polycephalum
1Institut für Allgemeine Mikrobiologie, University of Bern Baltzerstrasse 4, 3012 Bern, Switzerland 2Section of Biochemistry, Molecular and Cell Biology, Cornell University Ithaca, NY 14853, USA
Received May 17, 1983. Revised October 26, 1983. Accepted October 26, 1983.
We have used S1 nuclease to map the initiation site of ribosomal RNA transcription in the acellular slime mold Physarum polycephalum, and we have determined the sequence of 1011 nucleotides surrounding the start site. Consistent with others' observations, there is little homology with the comparable region of other species. As predicted by previous restriction mapping, direct repeats roughly 30 base pairs in length are present upstream of the initiation site and a 148 base pair duplication occurs in the external transcribed spacer. The results also suggest the presence of a processing site within the external transcribed spacer of the ribosomal transcription unit.