The structure of the protein known both as neuronal nitric oxide synthase inhibitory protein, PIN (protein inhibitor of nNOS), and also as the 8 kDa dynein light chain (LC8) has been solved by X-ray diffraction. Two PIN/LC8 monomers related by a two-fold axis form a rectangular dimer. Two pairs of α-helices cover opposite faces, and each pair of helices packs against a β-sheet with five antiparallel β-strands. Each five-stranded β- sheet contains four strands from one monomer and a fifth strand from the other monomer. A 13-residue peptide from nNOS is bound to the dimer in a deep hydrophobic groove as a sixth antiparallel β-strand. The structure provides key insights into dimerization of and peptide binding by the multifunctional PIN/LC8 protein.
ASJC Scopus subject areas
- Structural Biology