biostudies-literatureUnknownGuzman BBNHLBI NIH HHSNIGMS NIH HHSRNA binding proteins (RBPs) interact with and tightly regulate the fate of messenger RNAs but how RNA targets are recognized remains a challenging question. RBPs often contain multiple domains known to directly bind RNA, such as RNA recognition motifs (RRMs), as well as domains whose RNA binding capacity remains incompletely understood, <i>e.g.,</i> low complexity domains (LCDs). Here, we dissect HNRNPR, an RBP with three RRMs and an arginine-glycine rich (RG-rich) LCD. We apply unbiased high-throughput biochemical approaches and identify critical RNA binding domains that confer specificity. We show that not all RRMs contribute equally to binding and find that RRM3, along with a downstream C-terminal charged region, are required for RNA binding. We find that HNRNPR also binds RNA G-quadrupbioRxiv : the preprint server for biology2025.05.01.651718https://www.ebi.ac.uk/biostudies/studies/S-EPMC12247724biostudies-literatureContributions of Folded and Disordered Domains to RNA Binding by HNRNPR.PMC12247724R35 GM142864T32 HL007149T32 GM135095T32 GM148376T32 HL069768Martyr JGGuzman BBHu YCavazos FFGoda GADominguez DAleman MMJimenez AfalseContributions of Folded and Disordered Domains to RNA Binding by HNRNPR.RNA binding proteins (RBPs) interact with and tightly regulate the fate of messenger RNAs but how RNA targets are recognized remains a challenging question. RBPs often contain multiple domains known to directly bind RNA, such as RNA recognition motifs (RRMs), as well as domains whose RNA binding capacity remains incompletely understood, <i>e.g.,</i> low complexity domains (LCDs). Here, we dissect HNRNPR, an RBP with three RRMs and an arginine-glycine rich (RG-rich) LCD. We apply unbiased high-throughput biochemical approaches and identify critical RNA binding domains that confer specificity. We show that not all RRMs contribute equally to binding and find that RRM3, along with a downstream C-terminal charged region, are required for RNA binding. We find that HNRNPR also binds RNA G-quadrup2025-01-01T00:00:00Z2025 May2025-08-27T03:06:53.548Z2025-08-27T03:06:53.548ZS-EPMC122477244065489110.1101/2025.05.01.651718