Functions of the TFIIE-Related Tandem Winged-Helix Domain of Rpc34 in RNA Polymerase III Initiation and Elongation

Wei, Yi-Yu; Chen, Hung-Ta

doi:10.1128/mcb.00105-17

Cited by 11 publications

(11 citation statements)

References 40 publications

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“…5e ). C34 WH1 and WH2 domains are also stabilized over the cleft, consistent`with the recent report that mutations in the tandem WH domains of C34 reduce transcription elongation efficiency 54 . During the RNA extension step, the ZR domain and linker region of Brf1 need to be displaced, which may be achieved by the extending nascent RNA.…”

Section: Discussionsupporting

confidence: 90%

Structural visualization of RNA polymerase III transcription machineries

et al. 2018

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RNA polymerase III (Pol III) transcription initiation requires the action of the transcription factor IIIB (TFIIIB) and is highly regulated. Here, we determine the structures of Pol III pre-initiation complexes (PICs) using single particle cryo-electron microscopy (cryo-EM). We observe stable Pol III–TFIIIB complexes using nucleic acid scaffolds mimicking various functional states, in which TFIIIB tightly encircles the upstream promoter DNA. There is an intricate interaction between TFIIIB and Pol III, which stabilizes the winged-helix domains of the C34 subunit of Pol III over the active site cleft. The architecture of Pol III PIC more resembles that of the Pol II PIC than the Pol I PIC. In addition, we also obtain a 3D reconstruction of Pol III in complex with TFIIIB using the elongation complex (EC) scaffold, shedding light on the mechanism of facilitated recycling of Pol III prior to transcription re-initiation.

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Section: Discussionsupporting

confidence: 90%

Structural visualization of RNA polymerase III transcription machineries

et al. 2018

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“…RNAP III achieves this with stably associated subunit complexes that are homologous to dissociable transcription factors (TFs) used by RNAP II (2,4). RNAP III initiation-specific subunit heterotrimer, C31/34/82 is related to TFIIEα/β (5,6) while the heterodimer C37/53 is related to TFIIFα/β, and the RNAP I subunit heterodimer 49/34.5 (7,8). C37/53 and subunit C11 together promote facilitated recycling (9).…”

Section: Introductionmentioning

confidence: 99%

RNA polymerase III subunits C37/53 modulate rU:dA hybrid 3′ end dynamics during transcription termination

Mishra

Maraia

2018

Nucleic Acids Research

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RNA polymerase (RNAP) III synthesizes tRNAs and other transcripts, and mutations to its subunits cause human disorders. The RNAP III subunit-heterodimer C37/53 functions in initiation, elongation and in termination-associated reinitiation with subunit C11. C37/53 is related to heterodimers associated with RNAPs I and II, and C11 is related to TFIIS and Rpa12.2, the active site RNA 3′ cleavage factors for RNAPs II and I. Critical to termination is stability of the RNA:DNA hybrid bound in the active center, which is loose for RNAP III relative to other RNAPs. Here, we examined RNAP III lacking C37/53/C11 and various reconstituted forms during termination. First, we established a minimal terminator as 5T and 3A on the non-template and template DNA strands, respectively. We demonstrate that C11 stimulates termination, and does so independently of its RNA cleavage activity. We found that C37/53 sensitizes RNAP III termination to RNA:DNA hybrid strength and promotes RNA 3′ end pairing/annealing with the template. The latter counteracts C11-insensitive arrest in the proximal part of the oligo(T)-tract, promoting oligo(rU:dA) extension toward greater hybrid instability and RNA release. The data also indicate that RNA 3′ end engagement with the active site is a determinant of termination. Broader implications are also discussed.

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“…The heterodimer stimulates polymerase nuclease activity and has a triple ␤-barrel domain similar to the core of TFIIF and the pol III heterodimer of C37/C53 (42)(43)(44). The C terminus of yeast RPA49 contains a domain with dual-winged helices (tandemwinged helix, t-WH) (42) that is capable of DNA binding and resembles a similar element in TFIIE (42) and the pol III subunit RPC34 (45,46). Mutations within the tWH of RPA49 result in increased sensitivity to 6-azauracil and mycophenolic acid, defects in transcription elongation (47), and lower levels of recruitment of pol I and Rrn3 at the promoter (36,47).…”

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confidence: 99%