犬弓首蛔虫abcg-5基因的克隆及序列分析

Cloning and Sequence Analysis of the Full-Length abcg-5 Gene of Toxocara canis

研究犬弓首蛔虫(Toxocara canis,T.canis)腺苷三磷酸结合盒转运蛋白(ATP-binding cassette transporters, ABC)亚家族G5基因(abcg-5)的分子特征.根据犬弓首蛔虫基因组数据库中的Tc-abcg-5基因序列设计引物,通过PCR技术克隆Tc-abcg-5全长基因,并进行多重序列比对和种系发育进化树分析.结果表明:该基因全长为1 902 bp,编码633个氨基酸.功能结构域分析发现TcABCG5蛋白包含1个ABC转运蛋白结构域和6个跨膜区,同时发现了高度保守的Walker A和Walker B模体. GO分析显示ABCG5具有ATP结合和ATP酶活性.种系发育进化树分析显示TcABCG5与猪蛔虫进化关系较近,与哺乳动物进化关系较远.

To study the molecular characteristics of ATP-binding cassette sub-family G member 5(abcg-5) in Toxocara canis, the full-length coding sequence of Tc-abcg-5 gene was amplified using PCR amplification, multiple sequence alignment(MSA) was made and a phylogenetic tree was constructed. The results showed that the entire sequence of Tc-abcg-5 gene contained 1 902 bp, encoding a protein of 633 amino acids. TcABCG5 was found to contain one ABC transporter domain and six transmembrane regions. The highly conserved Walker A and Walker B motifs of the ABCG sub-family were also found. Gene ontology(GO) annotations showed that TcABCG5 had the molecular function of ATP binding and ATPase activity. Phylogenetic analysis indicated that TcABCG5 shared a high level of amino-acid sequence similarity with Ascaris suum, and shared a low level of amino-acid sequence similarity with mammals. This study is expected to lay a foundation for further functional researches of TcABCG5.