BIOL-UA 21 Lecture Notes - Lecture 17: Cpg Site, Cpg Oligodeoxynucleotide, Tata Box
Document Summary
Tethering = forming dna platform for the transcription initiation factors to bind. Downstream control tissue specific and temporal expression. Transcribed at lower late, compose 60% of the promoter gene. May find multiple transcription factors thus don"t control the start site precisely. Divergent transcription = can do transcription in both directions. In vertebrates, cs are methylated at cpg (c next to a g) Due to mutations converting methylated cs there is less cpg sequences than expected. In the sea of cpg deficient genome sequence. ~1000 bp and elevated g/c composition, little cpg depletion, frequently less c methylation. Less precise transcription start sites, more divergent transcription (transcription in both directions from the promoter) Some cpg islands contain tata box and promoter proximal. Eukaryotic basal promoter element consensus sequences sequences, some don"t. Consensus sequence for tata box differs per species but usually contain tata.