摘要
以重庆分离病毒株PRRSV-SCQ构建的包含SCQ株ORF2、ORF3、ORF4、ORF5、ORF6和ORF7 6个结构蛋白基因的cDNA文库质粒pRSF2、pRSF3、pRSF4、pRSF5、pRSF6和pRSF7为基础材料,通过Sanger′s双脱氧末端终止法进行核酸序列分析。测序结果表明,文库质粒DNA中分别含有PRRSV-SCQ株中为结构蛋白编码的阅读框ORF2、ORF3、ORF4、ORF5、ORF6和ORF7的完全序列,其起始密码子均为ATG,终止密码子分别为TGA、TAG、TGA、TAG、TAA和TGA。阅读框ORF2的cDNA片段长度为721 bp,ORF3的cDNA片段长度为764 bp,ORF4的cDNA片段长度为547 bp,ORF5的cDNA片段长度为621 bp,ORF6的cDNA片段长度为509 bp,ORF7的cDNA片段长度为436 bp。推导的蛋白质序列中,GP2、GP3、GP4、GP5、M和N蛋白的氨基酸数量分别为258,254,178,200,174 aa和123aa。每条多肽链都以甲硫氨酸为起始氨基酸。
Porcine reproductive and respiratory syndrome virus （PRRSV） owned 6 structural proteins, named GP2,GP3, GP4, GP5, M and N, and 6 open reading frames （ORF2-7） encoding for these proteins. On the basis of the PRRSV-SCQ isolate, the cDNA of each ORF was prepared by reverse transcription （RT）-PCR amplification from viral RNA and was inserted into the pMD18-T vector. These cloning plas- mids, designated pRSF2, pRSF3, pRSF4, pRSFS, pRSF6 and pRSF7 respectively, were sequenced. The results showed that each cDNA owned the same start codon ATG, and different end codons（the end codon is TGA,TAG,TGA, TAG, TAA and TGA,respectively, from ORF2 to ORFT）. The length of cDNA fragment is 721 bp, 764 bp, 547 bp, 621 bp, 509 bp and 436 bp,respectively,from ORF2 to ORF7. The peptide lengths of GP2, GP3, GP4, GP5, M and N proteins are composed of 258,254,178,200,174 aa and 123 aa,respectively, and the start acid of each peptide is Met.
出处
《动物医学进展》
CSCD
2006年第4期55-59,共5页
Progress In Veterinary Medicine
