牛ACAS2基因的电子克隆与序列分析

Electronic Cloning and Sequences Analyses of Bovine ACAS2 Gene

本研究以牛的乙酰辅酶A合成酶2（ACAS2）基因为研究对象，利用生物信息学方法和同源序列克隆技术，对牛的ACAS2基因进行了电子克隆和序列分析，并对推导出的ACAS2蛋白结构与性质进行了初步分析。实验结果：牛ACAS2基因的eDNA序列长2726 bp，包括了2106 bp的开放阅读框序列（ORF），54 bp的5非翻译区序列（5 UTR）和566 bp的3非翻译区序列（3′UTR），由702个氨基酸组成。该基因cDNA核苷酸编码区序列与人，猕猴，小鼠，黑猩猩，家犬ACAS2基因的相似性分别为91％，90％，87％，899，6，90％，90％，推导的氨基酸序列与人，猕猴，小鼠，黑猩猩，家犬的相似性分别为94％，94％，92％，94％，87％。以ACAS2基因eDNA编码区序列构建的分子进化树研究结果表明，牛的ACAS2基因在人，猕猴，小鼠，黑猩猩，家犬等物种中，与家犬的亲缘关系特别近。牛的ACAS2蛋白的三级结构包含7个跨膜结构-Cutoff模体，三个比较大的分别位于169～199位氨基酸，170-191位氨基酸和326—345位氨基酸处。

Bovine EST sequences were aligned using human ACAS2 cDNA sequence as a probe from cow EST database in NCBI website, and a cDNA sequence was obtained by splicing the overlapped EST. Sequence analysis and bioinformatics showed that the in silico cloned cDNA is 2726 base pairs long with an open reading frame（ORF） containing 2106 nucleotides encoding a protein of 702 amino acidsS＇untranslated region（UTR） is 54 bp, and 3′UTR is 566 bp containing a polyA tail. The CDS of the obtained bovine A- CAS2 gene showed 90%,90%, 87%, 91%, 89%identity with the corresponding rhesus monkey,dog , mouse,human and chimpanzee respectively. The deduced amino acid sequence showed 94%, 87%, 92%, 94%, 94% identity with the corresponding rhesus monkey ,dog,mouse ,human and chimpanzee respectively .Analyzed results for phylogenetic tree of the amino acid sequences of cattle ACAS2 and other ACAS2 proteins in human and other animals showed that ,among all species mentioned above ,the nearest relationship existed between cattle and dog compared chimpanzee to the relationship between cattle and other species.