title: Precursor De13.1 from Conus delessertii defines the novel G gene superfamily.
abstract: Peptide de13a was previously purified from the venom of the worm-hunting cone snail Conus delessertii from the Yucatán Channel, México. This peptide has eight cysteine (Cys) residues in the unique arrangement C-C-C-CC-C-C-C, which defines the cysteine framework XIII ("-" represents one or more non-Cys residues). Remarkably, δ-hydroxy-lysine residues have been found only in conotoxin de13a, which also contains an unusually high proportion of hydroxylated amino acid residues. Here, we report the cDNA cloning of the complete precursor De13.1 of a related peptide, de13b, which has the same Cys framework and inter-Cys spacings as peptide de13a, and shares high protein/nucleic acid sequence identity (87%/90%) with de13a, suggesting that both peptides belong to the same conotoxin gene superfamily. Analysis of the signal peptide of precursor De13.1 reveals that this precursor belongs to a novel conotoxin gene superfamily that we chose to name gene superfamily G. Thus far superfamily G only includes two peptides, each of which contains the same, distinctive Cys framework and a high proportion of amino acid residues with hydroxylated side chains.
authors: Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro 76230, Mexico. maguilar@servidor.unam.mx
authors: Manuel B
authors: MB
authors: Aguilar
authors: Ernesto
authors: E
authors: Ortiz
authors: Quentin
authors: Q
authors: Kaas
authors: Estuardo
authors: E
authors: López-Vera
authors: Baltazar
authors: B
authors: Becerril
authors: Lourival D
authors: LD
authors: Possani
authors: Edgar P Heimer
authors: EP
authors: de la Cotera
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D020916:Conotoxins / Q000737:chemistry / Q000235:genetics*; D052078:Conus Snail / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D020916:Conotoxins; D011498:Protein Precursors