MCB 250 Lecture Notes - Lecture 22: Eukaryotic Transcription, Regulatory Sequence, Sigma Factor

• School: University of Illinois
• Department: Molecular and Cell Biology
• Course: MCB 250
• Professor: J Slauch

Document Summary

Transcription in prokaryotes: dna is bound directly by polymerase complex, dna is bound by sigma factor subunit at 35 and 10 sequences, polymerase interacts directly with transcription factors, polymerase alone = basal transcription. Some important differences: eukaryotes have three different types of rna polymerase. We will focus on the regulation of rna pol ii, which transcribes protein-coding mrnas. In eukaryotes, rna polymerase alone is never sufficient for transcription. Introduction: eukaryotic promoters tend to be complex, i. e. the dna contains numerous cis-regulatory elements that can influence transcription from a single core promoter. Individual cis-regulatory elements are generally known as enhancers. They typically contain closely spaced binding sites for several different regulatory proteins: most enhancers are located upstream, i. e. 5" to the core promoter on the non-template strand. But some eukaryotic genes also have 3" enhancers: enhancers can work at a distance some are located up to 1 million base pairs (mbp) from the core promoter they regulate.