SNAP output for PDB entry 8b9k [SNAP web server]

PDB-id

8b9k; SNAP-derived features in text and JSON formats; DNAproDB

Class

RNA binding protein

Method

cryo-EM (4.04 Å)

Summary

cryo-EM structure of mle in complex with adp:alf4 and sl7moduuc RNA

Reference

Jagtap PKA, Muller M, Kiss AE, Thomae AW, Lapouge K, Beck M, Becker PB, Hennig J (2023): "Structural basis of RNA-induced autoregulation of the DExH-type RNA helicase maleless." Mol.Cell, 83, 4318-4333.e10. doi: 10.1016/j.molcel.2023.10.026.

Abstract

RNA unwinding by DExH-type helicases underlies most RNA metabolism and function. It remains unresolved if and how the basic unwinding reaction of helicases is regulated by auxiliary domains. We explored the interplay between the RecA and auxiliary domains of the RNA helicase maleless (MLE) from Drosophila using structural and functional studies. We discovered that MLE exists in a dsRNA-bound open conformation and that the auxiliary dsRBD2 domain aligns the substrate RNA with the accessible helicase tunnel. In an ATP-dependent manner, dsRBD2 associates with the helicase module, leading to tunnel closure around ssRNA. Furthermore, our structures provide a rationale for blunt-ended dsRNA unwinding and 3'-5' translocation by MLE. Structure-based MLE mutations confirm the functional relevance of our model for RNA unwinding. Our findings contribute to our understanding of the fundamental mechanics of auxiliary domains in DExH helicase MLE, which serves as a model for its human ortholog and potential therapeutic target, DHX9/RHA.