Biochemistry 2280A Lecture Notes - Rna Editing, Recombinant Dna, Operon

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2280A
• Professor: Michael Boffa

Document Summary

2018-2019: gene expression: genes expressed at different levels, essential for growth and differentiation (different cell types express different genes, disease often due to altered expression of genes. Elongation: transcription bubble moves downstream (5"-3"), with template dna rewinding behind, rna proceeds until reach terminator sequence. Termination: rna polymerase falls off when terminator sequence is reached, sigma rebinds with rnap and cycle is repeated. Turn genes on/off based on enviro conditions, not in eukaryotes: gene specific regulatory proteins, dynamic, can function in both pro/eukaryotes, negative: repressor (trp repressor, lac repressor, positive: activator (cap protein) When there is little tryptophan in cell environment. Complex when bound blocks rnap holoenzyme from promoter, stop transcription: complex = trp repressor and trp from environment, trp dissociates from repressor when trp is low, repressor cant bind to operator, Rnap holoenzyme can access promoter, transcription proceeds: what is the structural basis from trp regulation, repressor: 107 residue protein, 6 alpha helices, unstructured loops.