BIOL 200 Lecture 20: Eukaryotic Transcription I
Document Summary
Eukaryotic transcription only takes place in 3 organelles: All share common features: all are multimeric complexes. Have large & small subunits -- similar to e. coli subunits which are two beta, two alpha, one omega. In some mammalian genes, the upstream region can be very large. Sometimes can transcribe in diff. directions. very common in genes that are expressed all the time (i. e. housekeeping genes: they are on all the time!!) Promoter-proximal elements: sometimes found upstream of transcription start site, sometimes found in introns!!! (right after start site) => so, introns are not completely junk. Dna is bent so that genes that were very far away can be controlled. Tata box: present on a lot of promoters, in the same region (-31 to -26) Initiator (inr): in promoters that don"t have a tata box; tells pol where to bind and start transcription. Binds strongly to tata sequence of the tata-box.
