The hRPC62 subunit of human RNA polymerase III displays helicase activity

Leyla El Ayoubi , Hélène Dumay-Odelot (1) , Aleksandar Chernev , Fanny Boissier (2) , Lionel Minvielle-Sébastia (2) , Henning Urlaub (3) , Sébastien Fribourg (4) , Martin Teichmann (5)

1 LBPA - Laboratoire de Biologie et de Pharmacologie Appliquée
2 IBGC - Institut de biochimie et génétique cellulaires
3 MPI-BPC - Max Planck Institute for Biophysical Chemistry
4 ARN : régulations naturelle et artificielle
5 LKB (Lhomond) - Laboratoire Kastler Brossel

In Eukaryotes, tRNAs, 5S RNA and U6 RNA are transcribed by RNA polymerase (Pol) III. Human Pol III is composed of 17 subunits. Three specific Pol III subunits form a stable ternary subcomplex (RPC62-RPC39-RPC32α/β) being involved in pre-initiation complex formation. No paralogues for subunits of this subcomplex subunits have been found in Pols I or II, but hRPC62 was shown to be structurally related to the general Pol II transcription factor hTFIIEα. Here we show that these structural homologies extend to functional similarities. hRPC62 as well as hTFIIEα possess intrinsic ATP-dependent 3′-5′ DNA unwinding activity. The ATPase activities of both proteins are stimulated by single-stranded DNA. Moreover, the eWH domain of hTFIIEα can replace the first eWH (eWH1) domain of hRPC62 in ATPase and DNA unwinding assays. Our results identify intrinsic enzymatic activities in hRPC62 and hTFIIEα.

Domaines: Sciences du Vivant [q-bio]; Biochimie, Biologie Moléculaire; Biochimie [q-bio.BM]; Biologie moléculaire

Leyla El Ayoubi, Hélène Dumay-Odelot, Aleksandar Chernev, Fanny Boissier, Lionel Minvielle-Sébastia, et al.. The hRPC62 subunit of human RNA polymerase III displays helicase activity. Nucleic Acids Research, 2019, 47 (19), pp.10313-10326. ⟨10.1093/nar/gkz788⟩. ⟨hal-02349695⟩