title: Cloning and Genomic Characterization of a Natural Insecticidal Peptide LaIT1 with Unique DDH Structural Fold.
abstract: Two native peptides with disulfide-directed hairpin (DDH) fold, LaIT1 and LITX, were recently isolated from scorpion venom, a development that offered insights into exploring the evolutionary linkage between DDH and inhibitor cystine knot (ICK) peptides. In this work, we isolated and identified the full-length cDNAs of LaTI1, a representative member with DDH fold, and further determined its complete gene structure. The precursor organization of LaIT1 is similar to that of ICK peptides. The LaIT1 gene contains four exons interrupted by three unique introns and differed from ICK peptides, suggesting divergent genomic organizations of DDH peptides and ICK peptides. Phylogenetic analysis further showed that the "simple" DDH peptide originates from the "complex" ICK peptide, rather than the reverse. To the best of our knowledge, this is the first report on the genomic organization of DDH-fold peptides, and it presents new evidence of an evolutionary linkage between ICK and DDH peptides.
authors: Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Hubei University of Medicine, Hubei, People's Republic of China; State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, People's Republic of China. zychen@whu.edu.cn.
authors: Jing
authors: J
authors: Chen
authors: Yue
authors: Y
authors: Xu
authors: Mingkui
authors: M
authors: San
authors: Zhijian
authors: Z
authors: Cao
authors: Wenxin
authors: W
authors: Li
authors: Yingliang
authors: Y
authors: Wu
authors: Zongyun
authors: Z
authors: Chen
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics*; D000818:Animals; D003001:Cloning, Molecular; D047168:Cystine Knot Motifs / Q000235:genetics*; D007306:Insecticides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry / Q000235:genetics*; D010802:Phylogeny; D017510:Protein Folding; D012604:Scorpion Venoms / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D007306:Insecticides; C000604432:LaIT1 protein, Liocheles australasiae; D010455:Peptides; D012604:Scorpion Venoms
keywords: Disulfide-Directed β-Hairpin; Genomic Organization; Inhibitor Cystine Knot; Scorpion