Probable ATP-dependent RNA helicase DHX36 also known as DEAH box protein 36 (DHX36) or MLE-like protein 1 (MLEL1) or G4 resolvase (G4R1) or RNA helicase associated with AU-rich elements (RHAU) is an enzyme that in humans is encoded by the DHX36gene.
Structurally, RHAU is a 1008 amino acid-long modular protein. It consists of a ~440-amino acid helicase core comprising all signature motifs of the DEAH-box family of helicases with N- and C-terminal flanking regions of ~180 and ~380 amino acids, respectively. Like all the DEAH-box proteins, the helicase associated domain is located adjacent to the helicase core region and occupies 75% of the C-terminal region.
RHAU exhibits a unique ATP-dependent guanine-quadruplex (G4) resolvase activity and specificity for its substrate in vitro. RHAU binds G4-nucleic acid with sub-nanomolar affinity and unwinds G4 structures much more efficiently than double-stranded nucleic acid. Consistent with these biochemical observations, RHAU was also identified as the major source of tetramolecular RNA-resolving activity in HeLa cell lysates.
Previous work showed that RHAU associates with mRNAs and re-localises to stress granules (SGs) upon translational arrest induced by various environmental stresses. A region of the first 105 amino acid was shown to be critical for RNA binding and re-localisation to SGs.
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Vaughn JP, Creacy SD, Routh ED, et al. (2006). "The DEXH protein product of the DHX36 gene is the major source of tetramolecular quadruplex G4-DNA resolving activity in HeLa cell lysates". J. Biol. Chem. 280 (46): 38117–20. doi:10.1074/jbc.C500348200. PMID16150737.