Recognition of distinct RNA motifs by the clustered CCCH zinc fingers of neuronal protein Unkempt.
Murn, J., Teplova, M., Zarnack, K., Shi, Y., Patel, D.J.(2016) Nat Struct Mol Biol 23: 16-23
- PubMed: 26641712 
- DOI: https://doi.org/10.1038/nsmb.3140
- Primary Citation of Related Structures:  
5ELH, 5ELK - PubMed Abstract: 
Unkempt is an evolutionarily conserved RNA-binding protein that regulates translation of its target genes and is required for the establishment of the early bipolar neuronal morphology. Here we determined the X-ray crystal structure of mouse Unkempt and show that its six CCCH zinc fingers (ZnFs) form two compact clusters, ZnF1-3 and ZnF4-6, that recognize distinct trinucleotide RNA substrates. Both ZnF clusters adopt a similar overall topology and use distinct recognition principles to target specific RNA sequences. Structure-guided point mutations reduce the RNA binding affinity of Unkempt both in vitro and in vivo, ablate Unkempt's translational control and impair the ability of Unkempt to induce a bipolar cellular morphology. Our study unravels a new mode of RNA sequence recognition by clusters of CCCH ZnFs that is critical for post-transcriptional control of neuronal morphology.
Organizational Affiliation: 
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.