Kashyap M, Ganguly AK, Bhavesh NS. Structural delineation of stem-loop RNA binding by human TAF15 protein.
Sci Rep 2015;
5:17298. [PMID:
26612539 PMCID:
PMC4661536 DOI:
10.1038/srep17298]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/28/2015] [Indexed: 11/09/2022] Open
Abstract
Human TATA binding protein associated factor 2 N (TAF15) and Fused in sarcoma (FUS) are nucleic acid binding proteins belonging to the conserved FET family of proteins. They are involved in diverse processes such as pre-mRNA splicing, mRNA transport, and DNA binding. The absence of information regarding the structural mechanism employed by the FET family in recognizing and discriminating their cognate and non-cognate RNA targets has hampered the attainment of consensus on modes of protein-RNA binding for this family. Our study provides a molecular basis of this RNA recognition using a combination of solution-state NMR spectroscopy, calorimetry, docking and molecular dynamics simulation. Analysis of TAF15-RRM solution structure and its binding with stem-loop RNA has yielded conclusive evidence of a non-canonical mode of RNA recognition. Rather than classical stacking interactions that occur across nitrogen bases and aromatic amino acids on ribonucleoprotein sites, moderate-affinity hydrogen bonding network between the nitrogen bases in the stem-loop RNA and a concave face on the RRM surface primarily mediate TAF15-RRM RNA interaction. We have compared the binding affinities across a set of single-stranded RNA oligonucleotides to conclusively establish that RNA binding is dependent upon structural elements in the RNA rather than sequence.
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