• Specific DNA sequence located upstream (= in the 5′ region) of a gene that regulates transcription
• Contains AT-rich sequences (e.g., TATA box and CAAT box)
• Binding site for RNA polymerase II and several other transcription factors at the start of transcription
• Mutations at the site of promoters usually lead to severely decreased transcription rate.
• Promotors increase the replication activity at the origin of replication (ori)