Cry1A型杀虫晶体蛋白活性区的空间结构比较分析

对9种代表性Cry1A型杀虫晶体蛋白成员进行活性区空间结构的同源模建与比较分析.分析结果表明:Domain Ⅰ和Domain Ⅲ相对保守,其中,Domain Ⅰ整体走向及结构基本重叠,只有Cry1Aa和Cry1Af多了一个螺旋;Domain Ⅱ的主要差异体现在loop上;将Domain Ⅲ结构一致的成员Cry1Ab,Cry1Ad,Cry1Ae和Cry1Af归为一个亚型,其他5种成员归为另一个亚型.研究确定了影响Cry1A型杀虫晶体蛋白结构差异的关键氨基酸及关键结构片段.

Structural Comparison of Toxic Core of Cry1A-Type Insecticidal Crystal Proteins

The 3-D structure of the toxic core for all available 9 typical Cry1A proteins were constructed by the method of homology modeling. The structural differences among different Cry1A proteins indicated that Domain Ⅰ and Domain Ⅲ were more conservative than Domain Ⅱ. Structures of Cry1A Domain Ⅰ were almost identical except Cry1Aa and Cry1Af which had one more helix. The differences among the Cry1A Domain II were mainly located in loops. Structures of Domain Ⅲ of Cry1Ab, Cry1Ad, Cry1Ae and Cry1Af were consistent, thus these four Cry1A proteins and the other five were divided into two different subgroups. The results confirm that the key residues and motifs are important for the insecticidal activites of Cry1A proteins.