This domain is found in Roquin-1/2 from humans and in other eukaryotic RING-E3 ubiquitin ligases and transferases. These paralogous proteins Roquin-1/2 recruit the deadenylation and decapping machineries to initiate mRNA degradation. They play a central role in repressing autoimmunity. The ROQ domain, highly conserved, is required for RNA binding and shows a mostly helical structure with a small three-stranded beta-sheet. It bears a winged helix-turn-helix motif, which is involved in the binding of constitutive decay elements-containing stem-loop mRNAs [1-5].

1: Roquin binds microRNA-146a and Argonaute2 to regulate microRNA homeostasis. Srivastava M, Duan G, Kershaw NJ, Athanasopoulos V, Yeo JH, Ose T, Hu D, Brown SH, Jergic S, Patel HR, Pratama A, Richards S, Verma A, Jones EY, Heissmeyer V, Preiss T, Dixon NE, Chong MM, Babon JJ, Vinuesa CG; Nat Commun. 2015;6:6253. PMID:25697406

2: Structural basis for RNA recognition in roquin-mediated post-transcriptional gene regulation. Schlundt A, Heinz GA, Janowski R, Geerlof A, Stehle R, Heissmeyer V, Niessing D, Sattler M; Nat Struct Mol Biol. 2014;21:671-678. PMID:25026077

3: The ROQ domain of Roquin recognizes mRNA constitutive-decay element and double-stranded RNA. Tan D, Zhou M, Kiledjian M, Tong L; Nat Struct Mol Biol. 2014;21:679-685. PMID:25026078

4: Roquin binding to target mRNAs involves a winged helix-turn-helix motif. Schuetz A, Murakawa Y, Rosenbaum E, Landthaler M, Heinemann U; Nat Commun. 2014;5:5701. PMID:25504471

5: New Insights into the RNA-Binding and E3 Ubiquitin Ligase Activities of Roquins. Zhang Q, Fan L, Hou F, Dong A, Wang YX, Tong Y; Sci Rep. 2015;5:15660. PMID:26489670