Structure of a new nucleic-acid-binding motif in eukaryotic transcriptional elongation factor TFIIS
Jeon, Choon Ju
Yoon, Ho Sup
Weiss, Michael A.
Date of Issue1993
School of Biological Sciences
Transcriptional elongation involves dynamic interactions among RNA polymerase and single-stranded and double stranded nucleic acids in the ternary complex1–4. In prokaryotes its regulation pro-vides an important mechanism of genetic control1. Analogous eukaryotic mechanisms are not well understood5, but may control expression of proto-oncogenes6,7 and viruses, including the human immunodeficiency virus HIV-1 (ref. 8). The highly conserved euk-aryotic transcriptional elongation factor TFIIS9 enables RNA polymerase II (RNAPII) to read though pause or termination sites, nucleosomes and sequence-specific DNA-binding proteins10–14. Two distinct domains of human TFIIS, which bind RNAPII and nucleic acids, regulate read-through10 and possibly nascent transcript cleavage11–15. Here we describe the three-dimensional NMR16 structure of a Cys4 nucleic-acid-binding domain from human TFIIS9,10. Unlike previously characterized zinc modules17–21, which contain an α-helix, this structure consists of a three-stranded β-sheet. Analogous Cys4 structural motifs may occur in other proteins involved in DNA or RNA trans-actions22–24, including RNAPII itself25. This new structure, desig-nated the Zn ribbon, extends the repertoire of Zn-mediated peptide architectures26 and highlights the growing recognition of the β-sheet as a motif of nucleic-acid recognition27,28.
© 1993 Nature Publishing Group. This is the author created version of a work that has been peer reviewed and accepted for publication by Nature, Nature Publishing Group. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at:http://dx.doi.org/10.1038/365277a0