PT  - JOURNAL ARTICLE
AU  - Pravin Kumar Ankush Jagtap
AU  - Marisa Müller
AU  - Pawel Masiewicz
AU  - Sören von Bülow
AU  - Nele Merret Hollmann
AU  - Bernd Simon
AU  - Andreas W. Thomae
AU  - Peter B. Becker
AU  - Janosch Hennig
TI  - Structure, dynamics and roX2-lncRNA binding of tandem double-stranded RNA binding domains dsRBD1,2 of <em>Drosophila</em> helicase Maleless
AID  - 10.1101/466763
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 466763
4099  - http://biorxiv.org/content/early/2018/11/09/466763.short
4100  - http://biorxiv.org/content/early/2018/11/09/466763.full
AB  - Maleless (MLE) is an evolutionary conserved member of the DExH family of helicases in Drosophila. Besides its function in RNA editing and presumably siRNA processing, MLE is best known for its role in remodelling non-coding roX RNA in the context of X chromosome dosage compensation in male flies. MLE and its human orthologue, DHX9 contain two tandem double-stranded RNA binding domains (dsRBDs) located at the N-terminal region. The two dsRBDs are essential for localization of MLE at the X-territory and it is presumed that this involves binding roX secondary structures. However, for dsRBD1 roX RNA binding has so far not been described. Here, we determined the solution NMR structure of dsRBD1 and dsRBD2 of MLE in tandem and investigated its role in double-stranded RNA (dsRNA) binding. Our NMR data show that both dsRBDs act as independent structural modules in solution and are canonical, non-sequence-specific dsRBDs featuring non-canonical KKxAK RNA binding motifs. NMR titrations combined with filter binding experiments document the contribution of dsRBD1 to dsRNA binding in vitro. Curiously, dsRBD1 mutants in which dsRNA binding in vitro is strongly compromised do not affect roX2 RNA binding and MLE localization in cells. These data suggest alternative functions for dsRBD1 in vivo.