摘要
通过 RT- PCR和 DNA测序技术 ,克隆和测定了绍兴麻鸭的一种类似鸡白细胞介素 2 ( IL- 2 )基因的核苷酸序列 ,并构建了该基因编码蛋白的三维结构分子模型。结果显示 ,绍兴麻鸭的类似于鸡 IL - 2基因的核苷酸长度由 74 8个碱基组成 ,编码产物为由 14 0个氨基酸残基组成的多肽 ,编码产物中含有 2 1个氨基酸残基组成的信号肽。绍兴麻鸭的类似于鸡 IL- 2基因的核苷酸及编码产物 ,与鸡和火鸡 IL- 2的一致性分别为 71.4 %～ 72 .1%和 5 5 .0 %～ 5 7.9% ,与哺乳类等动物 IL- 2的一致性分别为 2 2 .1%～ 2 8.8%和 14 .3%～ 17.1%。对绍兴麻鸭的类似于鸡 IL- 2基因蛋白编码产物的系统进化树分析表明 ,其编码产物与鸡和火鸡 IL- 2具有较远的亲缘关系。绍兴麻鸭的类似于鸡 IL- 2基因编码产物的三维结构 ,预测由 4个α-螺旋结构和 2个β折叠组成。这些研究结果预示 ,鸭的类似于鸡 IL - 2基因编码产物 ,在生物学功能上与哺乳动物和其他禽类具有很大的差异。
The nucleic sequence of a lymphokine gene of Shaoxing(SX) duck homologous to chicken IL 2 was cloned, sequenced using RT PCR method and DNA sequencing techniques. Then the molecular model of three dimensional structure of the predicted mature protein was constructed. The results revealed that the SX duck lymphokine gene homologous to chicken IL2 was consistently 748bp in length, encoding for a predicted polypeptide of 140 amino acid residues, including a signal peptide with 21 amino acid residues. The nucleic and predicted amino acid sequences of SX duck lymphokine gene homologous to chicken IL2 shared 71 4 to 72 1% and 55 0 to 57 9% identities with chicken and turkey IL 2s, 22 1% to 28 8 %, and 14 3% to 17 1% with those of several mammalian and rodent species, respectively. Phylogenetic analysis showed little far relationships between the predicted amino acid sequence of SX duck lymphokine gene homologous to chicken IL 2, and chicken or turkey IL 2s. The tertiary structural model of the predicted amino acid sequence of SX duck lymphokine gene homologous to chicken IL 2 contained A, B, C and D four helix bundle structures and two β sheets. The results mentioned above indicated that the biological functions of the mature protein of the duck lymphokine gene homologous to chicken IL 2 were quite different from those of other birds and mammalian species.
出处
《中国兽医学报》
CAS
CSCD
北大核心
2003年第6期545-548,共4页
Chinese Journal of Veterinary Science
基金
国家自然科学基金重点项目 (3 0 2 3 0 2 70 )
杭州市科委重大攻关项目 (2 0 0 1112 A0 7)
