A TATA box is a DNA sequence that indicates where a genetic sequence can be read and decoded. Promoter region is the proximal area of transcription unit, which provides site for attachment of transcription factors ( σ factor) and RNA polymerase. It is present upstream at 5 ' end of coding strand. It has special structure; an AT rich area called TATA box or Pribnow box. The TATA box is able to define the direction of transcription and also indicates the DNA strand to be read. Related Theory The TATA box is named for its conserved DNA sequence, which is most commonly TATAAA. Many eukaryotic genes have a conserved TATA box located 25-35 base pairs before the transcription start site of a gene.