Pribnow box

The Pribnow box has a function similar to the TATA box that occurs in promoters in eukaryotes and 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 during prokaryotic transcription to allow access to the template strand. The AT-richness is important to allow this separation, since adenine and thymine are easier to break apart (not only due to fewer hydrogen bonds, but also due to weaker base stacking effects).

It is named after David Pribnow and Heinz Schaller.

Probability of occurrence of each nucleotide in E. coli