Question

While performing EMSA, in which situation will you see the band highest?

(a) You add TFIID, TFIIA and polymerase

(b) You add TFIID, TFIIB, TFIIF and polymerase

(c) You add TFIID, TFIIA, TFIIF and polymerase

(d) You add TFIIA, TFIIB, TFIIF and polymerase

This question was addressed to me during an interview.

The doubt is from Transcription in Eukaryotes : Transcription Factors in section Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

Correct answer is (b) You add TFIID, TFIIB, TFIIF and polymerase

To explain I would say: TFIID is absolutely necessary for any nucleation to take place at all. The complex formed by this composition is almost functional as TFIIA is not playing that important role. However, TFIIB and TFIID absence hugely effects the formation of pre-IC.