Molecular mechanism of the RNA helicase DHX37 and its activation by UTP14A in ribosome biogenesis

Structure of the DHX37-RNA complex in adenosine nucleotide-free state. (A) Schematic of the domain architecture of MmDHX37. The crystallized protein comprises residues 179–1150. (L) linker domain, (RecA1) RecA-like domain 1, (RecA2) RecA-like domain 2, (HA2) helicase-associated domain 2, (OB) Oligonucleotide-binding fold domain, (CTD) carboxy-terminal domain. (B) Overall structure of the MmDHX37^179–1150-U₁₀ RNA complex. The helicase is shown in cartoon format and colored according to the scheme in A. The bound RNA is colored black and shown in stick format. The amino-/carboxy- and 5′-/3′-termini of the DHX37 polypeptide and the RNA are indicated. 5′HP: 5′ hairpin motif. (C) Zoom-in view of RNA nucleotides U1–U4. Hydrogen bonding interactions are indicated with dashed black lines. (D) Zoom-in view of the 5′HP and RNA nucleotides U3–U7. (E) Zoom-in view of nucleotides U5–U8 binding to helicase motifs IV, Iva, and V. (F) Zoom-in view of nucleotides U8–U10 binding to helicase motif Ic. (G) Zoom-in view of nucleotides U9–U10 binding to helicase motif Ib (hook-turn).