1. Gene Expression *Protein coding gene *Gene expression Genes control inherited variation via: DNA, RNA and protein Phenotype *Gene DNAPhenotypeRNAProtein ReplicationTranscriptionTranslation

2. Brief overview of transcription:

3. Transcription *RNA polymerase (from E. coli )  2  ’  Core Sigma factor Holoenzyme

4. Transcription Functions of a prokaryotic promoter: 1.ON/OFF Switch 2.Speed Switch 3.Alignment

5. Binding of RNA Polymerase to Promoters How tightly does core enzyme vs. holoenzyme bind DNA?

6. Transcription Initiation

7. Transcriptional Elongation:

8. Termination of Transcription Inverted Repeats and Hairpins The repeat at right is symmetrical around its center shown with a dot A transcript of this sequence is self- complementary –Bases can pair up to form a hairpin as seen in the lower panel

9. Termination of Transcription *Rho-independent termination

10.  factor Termination of Transcription *Rho-dependent termination