The Pribnow box (also known as the Pribnow-Schaller box) is the sequence TATAAT of six nucleotides (thymine-adenine-thymine-etc.) that is an essential part of a promoter site on DNA for transcription to occur in bacteria. It is an idealized or consensus sequence—that is, it shows the most frequently occurring base at each position in a large number of promoters analyzed; individual promoters often vary from the consensus at one or more positions. It is also commonly called the -10 sequence, because it is centered roughly 10 base pairs upstream from the site of initiation of transcription.