back to Molecular Biology Homepage

back to Objectives and Outlines Page

Prokaryotic Transcriptional Regulation

Oct 20 and 23, 2000

---

Announcements:

• Our next assigned reading, Jacob et al, is on reserve at Watzek. Check the electronic reserves desk to see whether it has been posted yet (should be soon). There are no figures--just a data table--so the electronic version should be fine.
• Homework #6 (chapter 9) is online, and is due at noon on Friday, Oct 27th
• The DNA Strider manual that I distributed this week in lab is now online

Learning objectives for Fri 10/20 and Mon 10/23

Students should be able to…

1. Diagram the structure of the lac operon, including the binding sites of the lac repressor, CAP, and RNA polymerase (specific nucleotide locations are not necessary--just the overall organization will suffice.) In broad terms, explain the experimental technique that was used to determine these binding sites.
2. Explain the mechanism of action of the lac repressor and of CAP, and the regulation of each.
3. Given a particular set of experimental conditions, predict the level of expression of the lac operon. Explain your prediction.
4. As above, for a mutant strain of bacteria carrying a particular combination of alleles in the lac region. (This objective will be supported by our research reading for this unit--Jacob et al, which we'll discuss on October 30th.)
5. Explain the general structure and organization of a bacterial two-component regulatory system. Compare and contrast this with the regulation of the lac operon.

Outline (for Friday and Monday):

• Chapter 9 wrap-up: evolutionary advantages of repetitive DNA
• Chapter 10 intro: differential gene expression, possible levels of regulation, and the importance of transcriptional initiation as a point of control
• The lac operon
  • Lac repressor: its discovery and characterization
  • Protein-binding regions in the lac control region
  • Activation: discovery and characterization of CAP
  • Overview of lac regulation
• Other means of transcriptional regulation in prokaryotes: sigma factors and two-component systems

Coming next Wednesday and Friday: transcriptional initiation in eukaryotes

Chapter 10 sections we'll skip:

• not many--we're going to hit this one pretty hard
• you should judge which details are most important by emphasis in class and via the learning objectives
• we may skip some of the eukaryotic sections--to be determined next week

back to Objectives and Outlines Page

back to Molecular Biology Homepage