Distinct regions of Sp1 modulate DNA binding and transcriptional activation.
Sp1 is a sequence-specific DNA binding protein that activates RNA polymerase II transcription from promoters that contain properly positioned GC boxes. A series of deletion mutants of Sp1 were expressed in Escherichia coli and used to identify separate regions of the protein that are important for three different biochemical activities. The sequence-specificity of DNA binding was conferred by Zn(II) fingers, whereas a different region of Sp1 appeared to regulate the affinity of DNA binding. The E. coli-synthesized Sp1 was able to stimulate initiation of RNA synthesis in vitro, and at least two distinct segments of the protein contributed to its transcriptional activity.
Kadonaga
J T
JT
Howard Hughes Medical Institute, Department of Biochemistry, University of California, Berkeley 94720.
Courey
A J
AJ
Ladika
J
J
Tjian
R
R
D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D005796:Genes; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D009154:Mutation; D016329:Sp1 Transcription Factor; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D016329:Sp1 Transcription Factor; D014157:Transcription Factors