Interchangeable RNA polymerase I and II enhancers.
The RNA polymerase I (pol I) enhancer of Saccharomyces cerevisiae contains at least three elements commonly associated with RNA polymerase II (pol II) enhancers, binding sites for the transcriptional activators general regulatory factor 2 and autonomously replicating sequence-binding factor I, and a thymidine-rich element. When the particular form of the thymidine-rich element found in the pol I enhancer was placed in front of a pol II promoter, transcription was stimulated 43-fold, comparable to the effect of a powerful pol II activator such as Gal4. Conversely, when two copies of a thymidine-rich element from a pol II enhancer were placed upstream of a pol I promoter, transcription was stimulated 38-fold. This functional reciprocity of pol I and II enhancers may reflect similarities in the mechanisms of transcriptional activation. The pol I enhancer also contains an element that appears to be pol I-specific and prevent the activation of pol II.
Lorch
Y
Y
Department of Cell Biology, Stanford University School of Medicine, CA 94305.
Lue
N F
NF
Kornberg
R D
RD
D001483:Base Sequence; D004742:Enhancer Elements, Genetic; D004926:Escherichia coli / Q000235:genetics; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010957:Plasmids; D012318:RNA Polymerase I / Q000235:genetics*; D012319:RNA Polymerase II / Q000235:genetics*; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*
D015345:Oligonucleotide Probes; D012319:RNA Polymerase II; D012318:RNA Polymerase I