The Pribnow box has a function similar to the TATA box that occurs in promoters in eukaryotes(+archaea): it is recognized and bound by a subunit of RNA polymerase during initiation of transcription. This region of the DNA is also the first place where base pairs separate to allow access to one strand as the template for transcription. The AT-richness is important to allow this separation, since adenine and thymine pair together with only two hydrogen bonds (as opposed to three as with guanine and cytosine), they are easier to break apart.
| T | A | T | A | A | T |
| 82% | 89% | 52% | 59% | 49% | 89% |
The Pribnow box or Pribnow-Schaller box is named after David Pribnow and Heinz Schaller.