Biochemistry 2280A Lecture Notes - Lecture 3: Trp Operon, Lac Repressor, Lac Operon
25 Mar 2017
School
Department
Course
Professor
Document Summary
Two genes a and b- want differential transcription of a vs b. When these sigma"s are present they bind to the rna polymerase core and bind to the -35 and -10 subset of promoters: genes specific regulatory proteins: Dynamic: responsive to environmental changes (turning an individual promoter on or off in response to environment) Operator: a short region of dna found within a bacterial promoter that negatively regulates expression of the adjacent gene. Trp repressor: the protein that binds the trp operator. 5 genes are required for tryptophan biosynthesis are transcribed from a common promoter: makes the 5 enzymes that then make tryptophan. Trp operator binds a protein the trp repressor. Two key elements: trp operator located in between the -10 and -35 regions, dna element, trp repressor (protein that binds to operator, protein that binds to the dna. Trp repressor binds to tryptophan when theres lots of tryptophan in the cell.
