title: A structurally deviant member of the Euplotes raikovi pheromone family: Er-23.
abstract: Pheromones of Euplotes raikovi form a homologous family of proteins with 37- to 40-amino acid residues, including six cysteines that form three strictly conserved disulfide bridges. The determination of the primary structure of the pheromone Er-23, which was isolated from cells derived from natural populations of E. raikovi that secrete the other known pheromones, has now revealed a novel structure type. The polypeptide chain of this pheromone contains 51 residues, 10 of which are cysteines presumably involved in the formation of five disulfide bridges, and lacks a carboxyl-terminal tail following the last cysteine of the sequence. The elongation of the Er-23 molecule is presumed to result from multiple events of gene duplication starting from an ancestral motif Xxx(2-4)-Cys-Xxx(5-7)-Cys.
authors.affiliation: Dipartimento di Biologia Molecolare Cellulare Animale, University of Camerino, Italy.
authors.forename: Giuseppe Graziano
authors.initials: GG
authors.lastname: Di
authors.forename: Cristina
authors.initials: C
authors.lastname: Miceli
authors.forename: Ralph
authors.initials: R
authors.lastname: Zahn
authors.forename: Fred
authors.initials: F
authors.lastname: Damberger
authors.forename: Kurt
authors.initials: K
authors.lastname: Wüthrich
authors.forename: Pierangelo
authors.initials: P
authors.lastname: Luporini
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019075:Electrophoresis, Capillary; D016812:Euplotes / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010675:Pheromones / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein
chemical_list: D010675:Pheromones; D015800:Protozoan Proteins; C440428:pheromone Er-23, Euplotes raikovi