TY - JOUR
T1 - Weakening of the T7 promoter-polymerase interaction facilitates promoter release
AU - Guo, Qing
AU - Sousa, Rui
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005/4/15
Y1 - 2005/4/15
N2 - During transcription initiation, RNA polymerases retain interactions with their promoters until the RNA is extended to 8-13 nucleotides, at which point the polymerase releases the promoter and moves downstream. It has been shown that release of the T7 promoter is inhibited when the T7 RNA polymerase-promoter interaction is strengthened. Here we asked whether release would be facilitated when the T7 promoter-polymerase interaction is weakened by the introduction of promoter mutations known to reduce promoter activity. Using chemical and enzymatic probes to monitor the position of the polymerase as a function of RNA length, we found that promoter mutations upstream of -4 facilitated release of the polymerase from the promoter, but more downstream mutations did not have such effects. We also found that released complexes turn over more slowly than promoter-bound complexes, indicating that retention of promoter interactions contributes to the dissociation of short RNAs during initial transcription.
AB - During transcription initiation, RNA polymerases retain interactions with their promoters until the RNA is extended to 8-13 nucleotides, at which point the polymerase releases the promoter and moves downstream. It has been shown that release of the T7 promoter is inhibited when the T7 RNA polymerase-promoter interaction is strengthened. Here we asked whether release would be facilitated when the T7 promoter-polymerase interaction is weakened by the introduction of promoter mutations known to reduce promoter activity. Using chemical and enzymatic probes to monitor the position of the polymerase as a function of RNA length, we found that promoter mutations upstream of -4 facilitated release of the polymerase from the promoter, but more downstream mutations did not have such effects. We also found that released complexes turn over more slowly than promoter-bound complexes, indicating that retention of promoter interactions contributes to the dissociation of short RNAs during initial transcription.
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U2 - 10.1074/jbc.M500518200
DO - 10.1074/jbc.M500518200
M3 - Article
C2 - 15711016
AN - SCOPUS:17644414540
VL - 280
SP - 14956
EP - 14961
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 15
ER -