Overview Enhancer function allow signal transduced to ↑ transcription act by binding and bending DNA such that they can act on the promoter directly location may be very far from gene locus may be within gene locus orientation does not matter examples glucocorticoid response elements (GREs) bind glucocorticoid estrogen response elements (EREs) bind estrogen cAMP response element (CREs) bind cAMP Silencers act in a mechanism similar to enhancers but ↓ transcription Upstream promoter elements function allow transcription factor induced transcription ↑ location close to gene locus examples CCAAT box bind NF-1 TATA box 5'-UTR untranslated region upstream of start codon Kozak consensus sequence GCCGCCRCCAUGG, where R is A or G three bases upstream from AUG start codon plays a major role in initiation of translation a mutation in the Kozak consensus sequence may cause β-thalassemia intermedia Start codon codes for methionine (AUG) beginning of translated (coding) region Coding region between start codon and stop codon following transcription contains introns and exons (eukaryotes) Stop codon UGA, UAG, UAA terminates translation 3'-UTR untranslated region downstream of stop codon