title: Sperm coating mechanism from the 1.8 A crystal structure of PDC-109-phosphorylcholine complex.
abstract: Bovine seminal plasma PDC-109 binds to sperm surface choline lipids and promotes sperm capacitation by stimulating the efflux of cholesterol and phospholipids. The structure of PDC-109 with bound phosphorylcholine was solved using MAD data of a single platinum site. Its two globular (40 x 50 x 20 A(3)) Fn2 domains are linked and clustered by a short polypeptide. The choline binding sites lie at the same face of the molecule. Phosphorylcholine binds to the Fn2 domains through a cation-pi interaction between the quaternary ammonium group and a core tryptophan, plus hydrogen bonding between hydroxyls of exposed tyrosines and the phosphate group. The structure of the PDC-109-oPC complex provides a structural ground for the sperm membrane-coating mechanism underlying PDC-109-induced capacitation.
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
authors.forename: David A
authors.initials: DA
authors.lastname: Wah
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-Tornero
authors.forename: Libia
authors.initials: L
authors.lastname: Sanz
authors.forename: Antonio
authors.initials: A
authors.lastname: Romero
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Calvete
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D018360:Crystallography, X-Ray; D019281:Dimerization; D008024:Ligands; D008297:Male; D008566:Membranes / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D010767:Phosphorylcholine / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D029607:Seminal Vesicle Secretory Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013094:Spermatozoa / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008024:Ligands; D029607:Seminal Vesicle Secretory Proteins; C424303:seminal vesicle secretory protein 109, Bos taurus; D010767:Phosphorylcholine