trans-acting: RNA polymerase, repressor, TATA Binding Protein, TFIIB, CAP, tryptophan.

Is the promoter cis or trans?

Therefore the transcription initiation complex is composed of promoter sequences and DNA binding proteins. These two components of transcription are normally described as cis-acting elements and trans-acting factors.

What are trans-acting regulatory elements?

Trans-regulatory elements (TRE) are DNA sequences encoding upstream regulators (ie. trans-acting factors), which may modify or regulate the expression of distant genes. Trans-acting factors interact with cis-regulatory elements to regulate gene expression.