Question

TAF1: Which of the following statements is FALSE?

-The following activities are present in TAF1: HDAC, kinase, and ubiquitin activating/conjugation
-The TAN-1 domain mimics the TATAA of the promoter.
- The largest TAF, TAF1, is the only TAF with enzymatic activity.
- The TAN-1 domain binds the DNA binding surface of TBP, which is thought to inhibit TFIID recognition of TATAA promoters.

Answer 1

The false statement is that TAF1 is the only TAF with enzymatic activity; while TAF1 has multiple enzymatic functions, other TAFs also exhibit enzymatic activities, such as TAF9's HAT activity.

Step-by-step explanation:

The statement "The largest TAF1, TAF1, is the only TAF with enzymatic activity" is FALSE. TAF1 does posses multiple enzymatic activities including histone acetyltransferase (HAT), which is involved in chromatin remodeling. However, it is not correct to say that TAF1 is the only TAF with enzymatic activity. Other TAFs also have enzymatic functions; for instance, TAF9 contains HAT activity too.

The TAN-1 domain within TAF1 does not mimic the TATAA of the promoter but binds to the DNA binding surface of TBP, thereby inhibiting the recognition of TATAA promoters by TFIID. The other activities mentioned such as HDAC, kinase, and ubiquitin activating/conjugation are indeed present in TAF1. Therefore, the statement about the TAN-1 domain mimicking the TATAA sequence and the claim that TAF1 is the only TAF with enzymatic activity are misleading.