TITLE:
Characterization of the Novel Insecticidal Crystal Protein Cyt3Aa1 from Bacillus thuringiensis TD516
AUTHORS:
Jun Zhu, Zizhong Zhu, Baoli Zhang, Xu Liu, Yiping Liu, Aiping Zheng, Shiquan Wang, Shuangcheng Li, Qiming Deng, Huainian Liu, Yueyang Liang, Ting Zou, Aijun Wang, Lingxia Wang, Ping Li
KEYWORDS:
TD516, Cyt3Aa1, Activity Assays, Three-Dimensional Structure
JOURNAL NAME:
Advances in Microbiology,
Vol.10 No.7,
July
24,
2020
ABSTRACT: Bacillus thuringiensis (Bt) produces two families of insecticidal crystal proteins, i.e., crystalline (Cry) and cytolytic
(Cyt) toxins. Cyt3Aa1, the newest Cyt family member, is produced by Bt TD516.
Bioassay results have shown that Cyt3Aa1 has weak hemolytic activity against
human red blood cells and is not toxic to A. aegypti larvae, but causing a teratogenic effect. The three-dimensional
structure of Cyt3Aa1 has a typical cytolysin fold containing a β-sheet
held by two surrounding α-helical
layers, resembling the previously reported Cyt1Aa and Cyt2Aa structures, which
indicated that Cyt3Aa1 might be a membrane-perforation toxin and could induce
synergism with Cry protein. This study provides a new source of insecticidal
crystal proteins, and presents a foundation for understanding the biological
characterization of it, which will aid in the development of strategies to cope
with the potential problem of insect resistance.