BIO 327 Lecture Notes - Lecture 12: Regulatory Sequence, Transcriptional Regulation, Multicellular Organism
Document Summary
Gene expression: process by which cells selectively direct the synthesis of the many thousands of proteins and rnas encoded in genome. Dna in specialized cells of multicellular organisms still contain the entire set of instructions need to make a whole organism. Housekeeping proteins: proteins common to all the cells of a multicellular organism. Specialized cells can alter their patterns of gene expression in response to extracellular cues. Promoters include transcription initiation site where rna synthesis begins. They all have regulatory dna sequences that are used to switch the gene on or off. To have effect, must be recognized by transcription regulator to a regulatory dna sequence that acts as the switch to control transcription. Proteins that recognize a specific nucleotide sequence do so because the protein surface fits tightly against the surface features of the dna double helix. Dimerization doubles the area of contact with dna increases the strength and specificity of the protein-dna interaction.
