title: C-type lectin protein isoforms of Macrovipera lebetina: cDNA cloning and genetic diversity.
abstract: Snake venom contains a complex protein mixture belonging to a few well-characterized protein families: disintegrins, phospholipase A2, serine protease, l-amino acid oxidase, Zn-dependent metalloproteinase, natriuretic peptides, myotoxins, cysteine-rich secretory protein (CRISP) toxins, Kunitz-type protease inhibitors and C-type lectin-like. Despite their pharmacological importance, little is known about the exact composition of each protein family. We report here the cloning of 25 complete ORFs from Macrovipera lebetina transmediterranea venom gland that encodes several isoforms and novel C-type lectins (CTLs). 16 alpha and nine beta CTL chains were identified. Based on their sequence alignment, we categorized the 16 CTL alpha subunits into five groups and the nine CTL beta subunits into four groups to deduce the phylogenetic tree of M. lebetina transmediterranea CTLs. Sequence analysis revealed that they share a high degree of similarity with each other and with other snake venom CTLs. The M. lebetina transmediterranea CTL sequences described here contain a C-lectin carbohydrate recognition domain-like fold (C-lectin CRD-like) characterized by several conserved amino acid residues in their structure, especially the cysteine. Finally, based on the comparison of some Macrovipera CTL, we propose that some new CTL gene versions should have occurred through "domains shuffling" from former genes.
authors.affiliation: Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, Tunisia.
authors.forename: Jed
authors.initials: J
authors.lastname: Jebali
authors.forename: Amine
authors.initials: A
authors.lastname: Bazaa
authors.forename: Samah
authors.initials: S
authors.lastname: Sarray
authors.forename: Khemais
authors.initials: K
authors.lastname: Benhaj
authors.forename: Anis
authors.initials: A
authors.lastname: Karboul
authors.forename: Mohamed
authors.initials: M
authors.lastname: El Ayeb
authors.forename: Naziha
authors.initials: N
authors.lastname: Marrakchi
authors.forename: Ali
authors.initials: A
authors.lastname: Gargouri
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D003435:Crotalid Venoms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology; D014644:Genetic Variation; D037181:Lectins, C-Type / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017819:Viperidae / Q000235:genetics* / Q000502:physiology*
chemical_list: D003435:Crotalid Venoms; D018076:DNA, Complementary; D037181:Lectins, C-Type