BIOL 3450 Lecture 15: 13 February - Chapter 9 – Transcriptional Control of Gene Expression
Document Summary
Chapter 9 transcriptional control of gene expression. Primary purpose of gene control: execution of precise developmental decisions proper genes are expressed in proper cells during development, allow readjustments of gene expression as physiologically necessary nutritional, environmental, etc. 3 eukaryotic rna polymerases: rna pol i ribosomal rnas, rna pol ii makes pre-mrna, rna pol iii 5s rrna, trnas, small rnas. Regulatory elements in dna: promoters and enhancers. Role of dna methylation and histone modifications in transcriptional regulation and. Initiator -2 to +4 on strand: downstream promoter element - +28 to + 32, three types of pol ii promoters, tata box - prevalent in highly transcribed genes. Initiator no complete consensus sequence around start: cpg islands cg stretch of 20 to 50 nucleotides within ~100 bp upstream of start site region; genes transcribed at low rate. Directional transcription 5" to 3" sense transcript.
