What is the common consensus sequence found in the core promoter?

The common consensus sequence found in the core promoter is the TATA box. This sequence is typically located about 25 to 30 base pairs upstream from the transcription start site of many eukaryotic genes. The TATA box plays a critical role in the initiation of transcription by providing a binding site for transcription factors and RNA polymerase II, facilitating the assembly of the transcription initiation complex.

In contrast, intron sequences are non-coding regions that are spliced out of pre-mRNA during processing and do not contribute to the core promoter structure. The poly-A tail is a sequence of adenine nucleotides added to the 3' end of mRNA transcripts after transcription, serving functions like mRNA stability and export but is not part of the promoter. Exon junctions refer to the boundaries between exons in a mature mRNA transcript and also do not play a role in promoter function. Thus, the TATA box stands out as the key element associated with the core promoter, serving as a crucial site for the transcription machinery to successfully initiate gene expression.