A new chimeric protein, named WT-CIIA, was designed by connecting the proline-rich decapeptide PPPVPPYSAG to the C-terminus of the alpha-spectrin SH3 domain through a natural twelve-residue linker to obtain a single-chain model that would imitate intramolecular SH3-ligand interaction. The crystal structure of this fusion protein was determined at 1.7 Å resolution. The asymmetric unit of the crystal contained two SH3 globules contacting with one PPPVPPY fragment located between them. The domains are related by the two-fold non-crystallographic axis and the ligand lies in two opposite orientations with respect to the conservative binding sites of SH3 domains.

Key words: Chimeric protein; Spectrin SH3; Proline-rich peptide; X-ray; Structure.

This article can be cited as:
Liubov V. Gushchina, Azat G. Gabdulkhakov, Stanislav V. Nikonov, Vladimir V. Filimonov. High-Resolution Crystal Structure of Spectrin SH3 Domain Fused with a Proline-Rich Peptide J. Biomol Struct Dyn 29(3)485-495(2011).