中文摘要：

对9种代表性Cry1 A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 Cry1 Aa和 Cry1 Af多了一个螺旋；DomainⅡ的主要差异体现在loop上；将DomainⅢ结构一致的成员Cry1 Ab，Cry1 Ad，Cry1 Ae和Cry1 Af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 Cry1 A型杀虫晶体蛋白结构差异的关键氨基酸及关键结构片段。

英文摘要：

The 3？D structure of the toxic core for all available 9 typical Cry1 A proteins were constructed by the method of homology modeling.The structural differences among different Cry1 A proteins indicated that Domain Ⅰ and Domain Ⅲ were more conservative than Domain Ⅱ.Structures of Cry1 A Domain Ⅰ were al-most identical except Cry1 Aa and Cry1 Af which had one more helix.The differences among the Cry1 A Domain II were mainly located in loops.Structures of DomainⅢ of Cry1 Ab,Cry1 Ad,Cry1 Ae and Cry1 Af were con-sistent,thus these four Cry1 A proteins and the other five were divided into two different subgroups.The re-sults confirm that the key residues and motifs are important for the insecticidal activites of Cry1 A proteins.