Transcriptional Activities of Two Different forms of Human TFIIS

Abstract

Transcription Factor IIS(TFIIS) exerts influence on the transcript elongation by RNA polymerase II. Two different cDNA clones of human TFIIS have been found. If we compare the amino acid sequence in the coding region of these two clones, we can find one of the cDNA clone carry extra 21 amino acids at the N-terminal region of TFIIS. To identify the functional role of these additional amino acid sequence, we have expressed and purified two different forms of TFIIS in E. coli. The results of the comparison between these two proteins in the transcription elongation activities indicate that 21 amino acid sequence is not crucial for the function of TFIIS in our in vitro assay system. But we cannot rule out the possibility of their functional role(s) in vivo.