Abstract
We have evaluated the elongation rates, processivities, and abortive transcription characteristics of a set of T7 RNA polymerase mutants that map to the polymerase active site. The effects of these mutations on transcription are complex: they cause decreases in activity and processivity during both the processive and abortive phases of transcription and exhibit disproportionate decreases in activity and processivity on poly(dA)·poly(dT) or poly(dT) versus poly(dG)·poly(dC) templates. They also exhibit an increase in the proportion of slippage dependent poly(G) transcript synthesis during the initial stages of transcription. It is shown that these multiple, distinct effects on transcription can be attributed to decreases in the mutant enzymes' phosphodiester bond formation rates. Estimates of the decreases in these rates are derived from the measured transcript elongation rates and processivities of the mutant enzymes.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 25120-25128 |
| Number of pages | 9 |
| Journal | Journal of Biological Chemistry |
| Volume | 269 |
| Issue number | 40 |
| State | Published - Oct 7 1994 |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Characterization of a set of T7 RNA polymerase active site mutants. / Bonner, Gary; Lafer, Eileen M; Sousa, Rui J.
In: Journal of Biological Chemistry, Vol. 269, No. 40, 07.10.1994, p. 25120-25128.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Characterization of a set of T7 RNA polymerase active site mutants
AU - Bonner, Gary
AU - Lafer, Eileen M
AU - Sousa, Rui J
PY - 1994/10/7
Y1 - 1994/10/7
N2 - We have evaluated the elongation rates, processivities, and abortive transcription characteristics of a set of T7 RNA polymerase mutants that map to the polymerase active site. The effects of these mutations on transcription are complex: they cause decreases in activity and processivity during both the processive and abortive phases of transcription and exhibit disproportionate decreases in activity and processivity on poly(dA)·poly(dT) or poly(dT) versus poly(dG)·poly(dC) templates. They also exhibit an increase in the proportion of slippage dependent poly(G) transcript synthesis during the initial stages of transcription. It is shown that these multiple, distinct effects on transcription can be attributed to decreases in the mutant enzymes' phosphodiester bond formation rates. Estimates of the decreases in these rates are derived from the measured transcript elongation rates and processivities of the mutant enzymes.
AB - We have evaluated the elongation rates, processivities, and abortive transcription characteristics of a set of T7 RNA polymerase mutants that map to the polymerase active site. The effects of these mutations on transcription are complex: they cause decreases in activity and processivity during both the processive and abortive phases of transcription and exhibit disproportionate decreases in activity and processivity on poly(dA)·poly(dT) or poly(dT) versus poly(dG)·poly(dC) templates. They also exhibit an increase in the proportion of slippage dependent poly(G) transcript synthesis during the initial stages of transcription. It is shown that these multiple, distinct effects on transcription can be attributed to decreases in the mutant enzymes' phosphodiester bond formation rates. Estimates of the decreases in these rates are derived from the measured transcript elongation rates and processivities of the mutant enzymes.
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M3 - Article
C2 - 7929200
AN - SCOPUS:0028027513
VL - 269
SP - 25120
EP - 25128
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 40
ER -