title: Isolated ZP-N domains constitute the N-terminal extensions of Zona Pellucida proteins.
abstract: Zona Pellucida (ZP) domains have been found in a wide variety of extracellular proteins, in which they play essential role for polymerization. They are shared by the ZP proteins, which constitute the extracellular coat of animal eggs. Except from ZP3, constituting the primary sperm receptor, the ZP proteins possess, in addition to their C-terminal ZP domains, N-terminal extensions, which are thought to play an important role in the species-specific gamete recognition. Here, we show that these extensions are made of single or multiple copies of a small globular domain, which can be significantly related to the N-terminal region of ZP domains (ZP-N domains). This finding brings new insights into the molecular evolution of ZP proteins, which may have evolved around a common ZP-N architecture, and more generally into the noticeable sequence diversity of ZP-N domains, which can be found as isolated subunits or tightly associated with ZP-C domains to form complete, canonical ZP domains.
authors.affiliation: Département de Biologie Structurale, IMPMC UMR 7590, Universités Pierre et Marie Curie-Paris6, Paris, France. isabelle.callebaut@impmc.jussieu.fr
authors.forename: Isabelle
authors.initials: I
authors.lastname: Callebaut
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Mornon
authors.forename: Philippe
authors.initials: P
authors.lastname: Monget
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030562:Databases, Protein; D004527:Egg Proteins / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D016247:Information Storage and Retrieval; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment / Q000379:methods*; D020539:Sequence Analysis, Protein / Q000379:methods*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D015044:Zona Pellucida / Q000378:metabolism*; D000072216:Zona Pellucida Glycoproteins
chemical_list: D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C000606517:ZP3 protein, human; D000072216:Zona Pellucida Glycoproteins