| Autor: |
Hemming, Sally A., Jansma, David B., Macgregor, Pascale F., Goryachev, Andrew, Friesen, James D., Edwards, Aled M. |
| Zdroj: |
Journal of Biological Chemistry; November 2000, Vol. 275 Issue: 45 p35506-35511, 6p |
| Abstrakt: |
RNA polymerase II lacking the Rpb9 subunit uses alternate transcription initiation sites in vitroandin vivoand is unable to respond to the transcription elongation factor TFIIS in vitro. Here, we show thatRPB9has a synthetic phenotype with the TFIIS gene. Disruption of RPB9in yeast also resulted in sensitivity to 6-azauracil, which is a phenotype linked to defects in transcription elongation. Expression of the TFIIS gene on a high-copy plasmid partially suppressed the 6-azauracil sensitivity of Δrpb9cells. We set out to determine the relevant cellular role of yeast Rpb9 by assessing the ability of 20 different site-directed and deletion mutants of RPB9to complement the initiation and elongation defects of Δrpb9cells in vivo. Rpb9 is composed of two zinc ribbons. The N-terminal zinc ribbon restored the wild-type pattern of initiation start sites, but was unable to complement the growth defects associated with defects in elongation. Most of the site-directed mutants complemented the elongation-specific growth phenotypes and reconstituted the normal pattern of transcription initiation sites. The anti-correlation between the growth defects of cells disrupted for RPB9and the selection of transcription start sites suggests that this is not the primary cellular role for Rpb9. Genome-wide transcription profiling of Δrpb9cells revealed only a few changes, predominantly in genes related to metabolism. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
