Genome-wide analysis of TFIIB's role in termination of transcription.

This study provides evidence that the role of TFIIB extends beyond initiation to include the termination step of transcription. Using GRO-seq analyses, we compared terminator readthrough phenotype in mutant (TFIIB ) and the isogenic wild type (TFIIB ) strains. Approximately 74% of genes analyzed exhibited a 2-3-fold increase in readthrough of the poly(A)-termination signal in the TFIIB mutant compared to TFIIB cells. Mass spectrometry of affinity purified TFIIB from chromatin fraction found TFIIB exhibiting interaction with CF1A and Rat1 termination complexes in TFIIB cells. There was, however, a drastic decrease in TFIIB interaction with CF1A and Rat1 termination complexes in the TFIIB mutant. ChIP assays revealed about 90% decline in recruitment of termination factors in TFIIB mutant compared to wild type cells. The overall conclusion of these results is that TFIIB affects termination of transcription on a genome-wide scale, and TFIIB-termination factor interaction may play a crucial role in the process.