6yj6

From Proteopedia

Structure of the TFIIIC subcomplex tauA

Structural highlights

6yj6 is a 3 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 3.1Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

TFC4_YEAST TFIIIC mediates tRNA and 5S RNA gene activation by binding to intragenic promoter elements. Upstream of the transcription start site, TFIIIC assembles the initiation complex TFIIIB-TFIIIC-tDNA, which is sufficient for RNA polymerase III recruitment and function. Part of the tauA domain of TFIIIC that binds boxA DNA promoter sites of tRNA and similar genes. TFC4 is the TFIIIB-assembling subunit of TFIIIC and essential for viability.^[1] ^[2]

Publication Abstract from PubMed

Transcription factor (TF) IIIC is a conserved eukaryotic six-subunit protein complex with dual function. It serves as a general TF for most RNA polymerase (Pol) III genes by recruiting TFIIIB, but it is also involved in chromatin organization and regulation of Pol II genes through interaction with CTCF and condensin II. Here, we report the structure of the S. cerevisiae TFIIIC subcomplex tauA, which contains the most conserved subunits of TFIIIC and is responsible for recruitment of TFIIIB and transcription start site (TSS) selection at Pol III genes. We show that tauA binding to its promoter is auto-inhibited by a disordered acidic tail of subunit tau95. We further provide a negative-stain reconstruction of tauA bound to the TFIIIB subunits Brf1 and TBP. This shows that a ruler element in tauA achieves positioning of TFIIIB upstream of the TSS, and suggests remodeling of the complex during assembly of TFIIIB by TFIIIC.

Structure of the TFIIIC subcomplex tauA provides insights into RNA polymerase III pre-initiation complex formation.,Vorlander MK, Jungblut A, Karius K, Baudin F, Grotsch H, Kosinski J, Muller CW Nat Commun. 2020 Sep 30;11(1):4905. doi: 10.1038/s41467-020-18707-y. PMID:32999288^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Willis I, Schmidt P, Soll D. A selection for mutants of the RNA polymerase III transcription apparatus: PCF1 stimulates transcription of tRNA and 5S RNA genes. EMBO J. 1989 Dec 20;8(13):4281-8. PMID:2686985
↑ Marck C, Lefebvre O, Carles C, Riva M, Chaussivert N, Ruet A, Sentenac A. The TFIIIB-assembling subunit of yeast transcription factor TFIIIC has both tetratricopeptide repeats and basic helix-loop-helix motifs. Proc Natl Acad Sci U S A. 1993 May 1;90(9):4027-31. PMID:8387209
↑ Vorlander MK, Jungblut A, Karius K, Baudin F, Grotsch H, Kosinski J, Muller CW. Structure of the TFIIIC subcomplex tauA provides insights into RNA polymerase III pre-initiation complex formation. Nat Commun. 2020 Sep 30;11(1):4905. doi: 10.1038/s41467-020-18707-y. PMID:32999288 doi:http://dx.doi.org/10.1038/s41467-020-18707-y