Biochemistry 2280A Lecture Notes - Ribosomal Rna, Tata-Binding Protein, Transcription Factor Ii D
12 Dec 2012
School
Department
Course
Professor
Document Summary
Brandl lecture 2 notes: regulation of gene expression. Methods of regulation: some genes have better -10 and -35 sequences. These genes will be expressed at higher levels. Will recruit rna polymerase at higher efficiency. Sequences cannot be regulated; are stuck with that sequences throughout time: there is more than one sigma factor. The most prevalent is the housekeeping , 70. Others include 54 nitrogen metabolism, hs heat shock. Heat shock responds to high temperature, is induced and reacts with rna core enzyme: gene specific regulatory proteins. Can change genes in response to different environmental signals through these gene specific regulatory proteins. In e. coli the 5 genes for tryptophan biosynthesis are transcribed from a common promoter. The trp operon is regulated by the concentration of tryptophan in the environment. Trp operon is expressed when there is little tryptophan in the cellular environment.
