The hRPC62 subunit of human RNA polymerase III displays helicase activity

Nucleic Acids Res. 2019 Nov 4;47(19):10313-10326. doi: 10.1093/nar/gkz788.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate
  • DNA Helicases / chemistry
  • DNA Helicases / genetics
  • Humans
  • Protein Subunits / chemistry
  • Protein Subunits / genetics
  • RNA Polymerase III / chemistry*
  • RNA Polymerase III / genetics
  • Transcription Factors, TFII / chemistry
  • Transcription Factors, TFII / genetics*
  • Transcription, Genetic*


  • Protein Subunits
  • Transcription Factors, TFII
  • transcription factor TFIIE
  • Adenosine Triphosphate
  • POLR3C protein, human
  • RNA Polymerase III
  • DNA Helicases