title: Sequence diversity of T-superfamily conotoxins from Conus marmoreus.
abstract: Remarkable sequence diversity of T-superfamily conotoxins was found in a mollusk-hunting cone snail Conus marmoreus. The sequence of mr5a purified from the snail venom was determined, while six other sequences of Mr5.1a, Mr5.1b, Mr5.2, Mr5.3, Mr5.4a, and Mr5.4b were deduced from their corresponding cDNA cloned by RACE approach. mr5a of 10 amino acid residues is one of the shortest T-superfamily conotoxins ever found. They all share a typical (-CC-CC-) Cys pattern, a conserved signal peptide and a long 3'-untranslated region. A consensus Glu residue is preceded by the second two adjacent cysteines in all these toxins except in mr5a, whereas Mr5.1a, Mr5.1b, Mr5.4a and Mr5.4b are abundant in Trp residues. The identification of these highly divergent T-superfamily conotoxins will facilitate the understanding the relationship of their structure and function.
authors.affiliation: Institute of Biochemistry and Cell Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Han
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Jiang
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Miao
authors.forename: Ji-Sheng
authors.initials: JS
authors.lastname: Chen
authors.forename: Cheng-Wu
authors.initials: CW
authors.lastname: Chi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002681:China; D002851:Chromatography, High Pressure Liquid; D020916:Conotoxins / Q000235:genetics*; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D014644:Genetic Variation; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012908:Snails / Q000235:genetics*
chemical_list: D020916:Conotoxins; D017931:DNA Primers; D018076:DNA, Complementary