Figure 1
(A) Sequence similarity and conserved regions among the RNA recognition (RNP1) motif of several spliceosomal and other autoantigens. Homologous amino acid residues are represented in different colors. The conserved consensus pattern is shown under the sequences. (B) Structural similarity of the epitope 145–164 aa within the RNP1 motif of La/SSB with other autoantigens. Superimposed structures of the RNP1 regions of the autoantigens U2B″ RNP (PDB: 1A9N, (20)), U1A RNP (PDB: 1OIA, (19)), nucleolin (PDB: 1RKJ, (18)), hnRNP (PDB: 1 × 4B), and La/SSB (PDB: 1ZH5, (21)) are depicted (on the left) in complex with a UUUOH-RNA dimer obtained from structure 1ZH5 (shown in yellow). The homologous regions with the La/SSB epitope are represented as ribbons with different colors, and their electrostatic potential is depicted on the right (positive charges in blue color, negative charges in red, and neutral regions in gray). All structures obtained from the PDB database.