FIGURE 2.

NMR analysis of the human PHAX-RBD domain. (A) ¹H,¹⁵N NMR spectra of human PHAX-RBD in the absence (black) and presence (red) of a U9 RNA oligonucleotide. (B) Sequence alignment and secondary structure of the human PHAX and C. parvum RNA_GG_bind domains. (#) Residues in human PHAX-RBD that show intermolecular NOEs with the AUCG RNA ligand. (C) Secondary chemical shifts and ¹⁵N relaxation data of the human PHAX-RBD bound to U9 RNA. ¹H,¹⁵N heteronuclear NOE and ¹⁵N T₁, T₂ relaxation data indicate that the protein–RNA complex tumbles as a monomer in solution.