Ty3 integrates into the transcription initiation sites of genes transcribed by RNA polymerase III. It is known that transcription factors (TF) IIIB and IIIC are important for recruiting Ty3 to its sites of integration upstream of tRNA genes, but that RNA polymerase III is not required. In order to investigate the respective roles of TFIIIB and TFIIIC, we have developed an in vitro integration assay in which Ty3 is targeted to the U6 small nuclear RNA gene, SNR6. Because TFIIIB can bind to the TATA box upstream of the U6 gene through contacts mediated by TATA-binding protein (TBP), TFIIIC is dispensable for in vitro transcription. Thus, this system offers an opportunity to test the role of TFIIIB independent of a requirement of TFIIIC. We demonstrate that the recombinant Brf and TBP subunits of TFIIIB, which interact over the SNR6 TATA box, direct integration at the SNR6 transcription initiation site in the absence of detectable TFIIIC or TFIIIB subunit B". These findings suggest that the minimal requirements for pol III transcription and Ty3 integration are very similar.

• PMID: 10882723
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Reference Type

Journal Article | Research Support, Non-U.S. Gov't | Research Support, U.S. Gov't, P.H.S.

Authors

Yieh L, Kassavetis G, Geiduschek EP, Sandmeyer SB

Primary Lit For

SNR6 | BRF1 | BDP1 | SPT15 | General transcription factor TFIIIB complex | General transcription factor TFIIIC complex | DNA-directed RNA polymerase III complex

Additional Lit For

TFC3 | TFC1 | TFC6 | TFC4 | TFC8 | TFC7

Review For