Contributions of the TATA box sequence to rate-limiting steps in transcription initiation by RNA polymerase II.
We have examined the role of the TATA box in determining transcription initiation frequency in vitro by studying a collection of promoters containing different TATA sequences in the context of the adenovirus major late promoter. In addition to measuring transcription rates, we have determined how the sequence changes affected the association and dissociation kinetics and the affinity of TBP binding. We observed that transcription from promoters containing the highest affinity TATA boxes is limited by the rate with which TBP associates with the promoter. In contrast, transcription from promoters containing lower affinity TATA boxes appears to be limited both by how much TBP is bound and by the relatively low occupancy of the conformation that can undergo subsequent steps in preinitiation complex assembly. The implications of these results in understanding the mechanism of transcription enhancement by transcriptional activators is discussed.
Hoopes
B C
BC
Institute of Molecular Biology and Department of Chemistry, University of Oregon, Eugene, OR 97403, USA.
LeBlanc
J F
JF
Hawley
D K
DK
D000256:Adenoviridae / Q000235:genetics; D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009154:Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012319:RNA Polymerase II / Q000235:genetics*; D006163:Ribonuclease T1 / Q000378:metabolism; D016385:TATA Box / Q000502:physiology*; D035181:TATA-Box Binding Protein; D013816:Thermodynamics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*; D015533:Transcriptional Activation / Q000502:physiology; D014764:Viral Proteins
D004268:DNA-Binding Proteins; C051096:MLTF protein, adenovirus; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; D014764:Viral Proteins; D012319:RNA Polymerase II; D006163:Ribonuclease T1