title: The theoretical three-dimensional structure of Bacillus thuringiensis Cry5Aa and its biological implications.
abstract: Cry5Aa is a crystal protein produced by Bacillus thuringiensis serovar. damstadiensis during its stationary phase, this delta-endotoxin is active against nematodes and has great potential for nematodes control. The theoretical model of the three-dimensional structure of Cry5Aa was predicted by homology modeling on the structures of the Cry1Aa which is specific to Lepidopteran insects. The structure of the Cry5Aa resembles previously reported Cry toxin structures but shows the following distinctions. Cry5Aa has a long insertion in alpha2 of domain I. Some loops in the domain II and III of Cry5Aa are exposed to the solvent. In this work we give a brief description of our model and hypothesize the residues of the Cry5Aa that could be important in receptor recognition and pore formation. This model will be helpful for the design of mutagenesis experiments aimed to the improvement of toxicity, and lead to a deep understanding of the mechanism of action of nematicidal toxins.
authors.affiliation: Key Laboratory of Microbial Molecular Biology of Hunan Province, College of Life Science, Hunan Normal University, Changsha, 410081, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Xin-Min
authors.forename: Xia
authors.initials: X
authors.lastname: Li-Qiu
authors.forename: Ding
authors.initials: D
authors.lastname: Xue-Zhi
authors.forename: Wang
authors.initials: W
authors.lastname: Fa-Xiang
mesh_terms: D000595:Amino Acid Sequence; D000969:Antinematodal Agents; D001413:Bacillus thuringiensis / Q000737:chemistry* / Q000235:genetics; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D003198:Computer Simulation; D004731:Endotoxins / Q000737:chemistry* / Q000235:genetics; D006460:Hemolysin Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D055672:Static Electricity
chemical_list: D000969:Antinematodal Agents; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis