Practice question

Promoter deletion analysis uses reporter fusions to map cis-elements. Wild-type promoter driving luciferase set as 100% activity. Progressive 5' deletions may reduce activity if activator site removed, indicating positive element. Unexpected increase above 100% suggests removed fragment contained repressive sequence or competing site, unmasking strong enhancer in retained portion. In GAL analyses, deleting Mig1 binding sites elevated expression in glucose while retaining UASG produced hyperactive constructs. Therefore constructs exceeding wild-type infer presence of enhancer module now freed from inhibitory context or repositioned closer to TATA box boosting transcription beyond normal constraints observed experimentally.