title: The theoretical 3D structure of Bacillus thuringiensis Cry5Ba.
abstract: Cry5Ba is a delta-endotoxin produced by Bacillus thuringiensis PS86A1 NRRL B-18900. It is active against nematodes and has great potential for nematode control. Here, we predict the first theoretical model of the three-dimensional (3D) structure of a Cry5Ba toxin by homology modeling on the structure of the Cry1Aa toxin, which is specific to Lepidopteran insects. Cry5Ba resembles the previously reported Cry1Aa toxin structure in that they share a common 3D structure with three domains, but there are some distinctions, with the main differences being located in the loops of domain I. Cry5Ba exhibits a changeable extending conformation structure, and this special structure may also be involved in pore-forming and specificity determination. A fuller understanding of the 3D structure will be helpful in the design of mutagenesis experiments aimed at improving toxicity, and lead to a deep understanding of the mechanism of action of nematicidal toxins.
authors.affiliation: Key Laboratory for Microbial Molecular Biology of Hunan Province, College of Life Science, Hunan Normal University, Changsha 410081, China. xialq@hunnu.edu.cn
authors.forename: Li-Qiu
authors.initials: LQ
authors.lastname: Xia
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Zhao
authors.forename: Xue-Zhi
authors.initials: XZ
authors.lastname: Ding
authors.forename: Fa-Xiang
authors.initials: FX
authors.lastname: Wang
authors.forename: Yun-Jun
authors.initials: YJ
authors.lastname: Sun
mesh_terms: D000595:Amino Acid Sequence; D024322:Amino Acids, Aromatic; D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry*; D004731:Endotoxins / Q000737:chemistry*; D006460:Hemolysin Proteins / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D008962:Models, Theoretical; D008969:Molecular Sequence Data; D010572:Pest Control, Biological; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity
chemical_list: D024322:Amino Acids, Aromatic; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis