Question

The majority of eukaryotic genes lack recognizable transcription initiation elements (TATA, BRE, INR, etc). How do you imagine transcription begins at the correct transcriptional start site when these elements are absent?

Answer 1

The majority of eukaryotic genes lack recognizable transcription initiation elements and certain genes such as the group of housekeeping gene possess promoters that are found within the CpG islands and therefore do not have proper recognizable core promoter elements to direct the transcription.In such cases,there occurs direct transcription initiation from multiple dispersed transcription start sites(TSSs).There are presence of TCT elements found at the TSS of these genes.This TCT element is recognized by the gene-specific TBP-related factor 2 (TRF2) and not by the usual TBP/TFIID to initiate the transcription process.