Tata box

TATA box is a DNA sequence that indicates where a genetic sequence can be read and decoded. It is a type of promoter sequence, which specifies to other molecules where transcription begins. Transcription is a process that produces an RNA copy of a DNA strand. The TATA box is named for its conserved DNA sequence, which is most commonly 'TATAAA'.

Function

The TATA box is crucial for the initiation of base pairing and transcription. It is recognized and bound by a transcription factor known as TATA-binding protein (TBP), which assists in the recruitment of RNA polymerase II and other proteins required for transcription. This assembly of proteins and RNA polymerase on the promoter sequence is known as the transcription preinitiation complex.

Location

The TATA box is typically located 25-30 base pairs upstream of the transcription start site. Its location can vary considerably among different genes, however. Despite its name, the TATA box does not necessarily contain the exact sequence 'TATAAA', and the sequence can vary among different organisms and tissues.

Variations

While the TATA box is a common type of promoter sequence, not all genes use it. Some genes have a TATA-less promoter, which lacks a TATA box and instead contains other sequences that direct the initiation of transcription. These other sequences can include initiator elements (Inr), downstream promoter elements (DPE), and CpG islands.

See also

• Promoter (genetics)
• Transcription (biology)
• Transcription factor
• RNA polymerase