论文部分内容阅读
从水稻矮缩病毒(rice dwarf virus,RDV)中国福建分离物中分离出第四号片段S4的双链RNA。以人工合成的两段寡聚核苷酸链为引物,经反转录合成cDNA,然后利用PCR技术扩增了编码区cDNA,将扩增产物分成两段克隆到pGEM3Zf(-)和pBluescript上。经限制性内切酶分析,进而进行亚克隆和序列测定。将这两段克隆进行连接,得到了具有S4编码区全长cDNA的克隆。对S4编码区全长序列及其相应的氨基酸序列用DNASIS和PROSIS软件系统进行分析,结果表明:(1)S4克隆片段全长由2217个碱基组成,包含一个编码727个氨基酸的完整开放阅读框架,与RDV日本分离物S4相比,核苷酸和氨基酸序列的同源率分别为92.2％和93.9％;(2)S4编码蛋白序列含有GTP-binding模式,以及两段符合Zinc-finger模式韵序列,但这个GTP-binding模式和其中之一Zinc-finger模式并不存在于伤瘤病毒(WTV)S4编码的蛋白的序列中。
Double stranded RNA of fragment S4 was isolated from rice dwarf virus (RDV) Fujian isolates in China. The two synthetic oligonucleotides were used as primers to synthesize cDNA by reverse transcriptase. Then the coding region cDNA was amplified by PCR. The amplified product was cloned into pGEM3Zf (-) and pBluescript. Restriction endonuclease analysis followed by subcloning and sequencing. The two clones were ligated to obtain a clone with the full-length cDNA of the S4 coding region. The full length sequence of S4 coding region and its corresponding amino acid sequence were analyzed by DNASIS and PROSIS software system. The results showed that: (1) The full length of S4 clone was composed of 2217 bases, including a complete open reading frame of 727 amino acids Compared with RDV Japan isolate S4, the homology of nucleotide and amino acid sequences were 92.2% and 93.9% respectively. (2) The S4 coding protein sequence contained GTP-binding pattern and two segments of Zinc-finger pattern However, this GTP-binding pattern and one of the Zinc-finger patterns is not found in the sequence of the protein encoded by the oncolytic virus (WTV) S4.