I was wondering if promoter sequences are located on 5'UTR region in eukaryotic organisms?

  • 2
    $\begingroup$ as i understand, UTR is part of mRNA (UnTranslated Region), whereas promoters are part of DNA, sequences where DNA-dependent RNA polymerase binds. So by definition, promoters can't be in UTR. More than that, since RNA Pol binds to promoter, only part of promoter sequence can be transcribed if any at all $\endgroup$ – aaaaaa Sep 15 '15 at 15:29

Most promoter elements are not a part of the mRNA sequence. They are upstream (towards 5') of the transcription start site. However, a certain class of promoters called downstream promoter elements (DPE) can overlap with the geneic region. These elements have been reported to lie at 29-33bp upstream of the transcription start site and widely employed, in Drosophila [1]. Mapping of DPEs has been done for mouse human genes as well [2]. However, a detailed analysis supported by good sequencing data is yet to be done.

So, though DPEs are present in the transcript, I am not sure if they are retained in the exon. This can be confirmed by mapping the splice sites but this analysis is not presented in these papers.

You can see from the below figure [3] that most first exons in humans are big enough to harbour the DPE.

enter image description here


I do not think promoter sequences are on 5'UTR region. 5' end of 5'UTR is the transcriptional start site and the general transcription factor binds to immediately upstream of the 5' end on the genome (about 30 to 40bp upstream).



Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.