0
$\begingroup$

I know that DNA binding transcription factors are trans-acting, but what about general transcription factors? Are they cis or trans acting?

$\endgroup$
  • $\begingroup$ Hi there and welcome to biology.se. For this site users are expected to do a little background reading before asking a question. What sources have you looked at that lead to this question? $\endgroup$ – James Nov 19 '15 at 2:43
  • $\begingroup$ From Wikipedia: A defining feature of transcription factors is that they contain one or more DNA-binding domains (DBDs), which attach to specific sequences of DNA adjacent to the genes that they regulate. So, there's no differentiation between "DNA-binding transcription factors" and "general transcription factors". In order to be classified as a TF, a protein must be capable of directly binding DNA. $\endgroup$ – MattDMo Nov 20 '15 at 15:46
2
$\begingroup$

When we say trans we mean that a diffusible factor, or agent is involved. So a molecule synthesized at one location, that can have a regulatory role in another location in the cell is said to be a "trans-acting" factor.

When we say cis we mean physically linked to, in such a way that the biological regulation only affects other molecules that are attached (in other words, something that is "cis-acting" cannot be freely diffusible).

So prokaryotic operators or promoters, and eukaryotic enhancers and promoters would be examples of cis-acting sequences, or elements. All protein transcription factors, or even DNA-binding proteins, are therefore trans-acting.

$\endgroup$
1
$\begingroup$

General transcriptional factor complexes bind to DNA at promoters of genes via DNA binding proteins such as TATA-binding protein.

It is quite clear that it is trans-acting.

$\endgroup$
  • $\begingroup$ I agree, all transcription factors are trans-acting. I just am not sure that I agree with you first sentence completely. Some of the proteins bind to other proteins and don't themselves have a DNA binding domain. I might be wrong in the sense that these proteins may not be canonically considered TFs, but they do exist. $\endgroup$ – AMR Nov 19 '15 at 3:47

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.