Sonntag K C, Darai G
Institut für Medizinische Virologie, Universität Heidelberg, Germany.
Virus Genes. 1992 Nov;6(4):333-42. doi: 10.1007/BF01703082.
The structure of the third origin of DNA replication (CIV-ori-M) of the genome (209 kbp) of Chilo iridescent virus (CIV) was determined by DNA nucleotide sequence analysis. The CIV-ori-M is located within the DNA sequences of the EcoRI CIV DNA fragment M (7 kbp; 0.310-0.345 viral map units) between the genome coordinates 0.310 (EcoRI site) and 0.317 (NcoI site). The DNA nucleotide sequence of the EcoRI/NcoI CIV DNA fragment (1601 bp) was determined for identifying the DNA sequence of the corresponding origin of DNA replication. The analysis of the DNA sequences of this region revealed the presence of a 12-mer inverted repeat at nucleotide positions 485-496 and 503-513 (485-AGATATTTGACT-496-TATGT-503-AGTCAAATATCT-513) that are able to form a hairpin-loop structure. A double-stranded DNA fragment was synthesized that corresponds to the nucleotide positions 485-513 that were cloned into the phages M13mp18 and M13mp19, and were screened for their ability to be amplified in CF-124 cell cultures infected with CIV. The successful amplification of the DNA sequence of the CIV-ori-M is strong evidence that this particular region of the CIV genome indeed serves as the origin of DNA replication.
通过DNA核苷酸序列分析确定了稻纵卷叶螟虹彩病毒（CIV）基因组（209 kbp）的第三个DNA复制起点（CIV-ori-M）的结构。CIV-ori-M位于EcoRI CIV DNA片段M（7 kbp；0.310 - 0.345病毒图谱单位）的DNA序列内，在基因组坐标0.310（EcoRI位点）和0.317（NcoI位点）之间。测定了EcoRI/NcoI CIV DNA片段（1601 bp）的DNA核苷酸序列，以鉴定相应DNA复制起点的DNA序列。对该区域DNA序列的分析揭示，在核苷酸位置485 - 496和503 - 513处存在一个12聚体反向重复序列（485 - AGATATTTGACT - 496 - TATGT - 503 - AGTCAAATATCT - 513），该序列能够形成发夹环结构。合成了一个对应于核苷酸位置485 - 513的双链DNA片段，将其克隆到噬菌体M13mp18和M13mp19中，并筛选它们在感染CIV的CF - 124细胞培养物中被扩增的能力。CIV-ori-M DNA序列的成功扩增有力地证明了CIV基因组的这一特定区域确实作为DNA复制起点。
