Kulkosky J, Katz R A, Skalka A M
Fox Chase Cancer Center, Institute for Cancer Research, Philadelphia, PA 19111.
J Acquir Immune Defic Syndr (1988). 1990;3(9):852-8.
The termini of integrated retroviral DNAs are characterized by highly conserved dinucleotide sequences: 5'TG...//...CA3'. For the avian and murine C-type retroviruses, the dinucleotide sequences reside two deoxynucleotides (usually AA and TT) from the LTR ends of unintegrated viral DNA (5' AATG...//...CATT3'). The number and identity of terminal deoxynucleotides in unintegrated HIV-1 linear DNA that extend beyond the conserved dinucleotides have not been determined. However, they had been presumed to consist of a single nucleotide (5'CTG...//...CAG3') on each end, based on inspection of the nucleotide sequence between the end of the supposed primer sites for retroviral DNA synthesis and the conserved proviral termini. We have utilized the polymerase chain reaction (PCR) to amplify segments representing the joined ends of linear DNA present in covalently closed circular HIV-1 DNA molecules isolated from infected T cells. These fragments were cloned and the nucleotide sequence of the LTR-LTR circle junction of several independent clones determined. Based upon the results, we predict that, like the avian and murine viruses, HIV-1 linear DNA contains two nucleotides beyond the conserved dinucleotides: 5'ACTG...//...CAGT3'. Models for the origin of these termini and other observed junction sequences are proposed.
整合的逆转录病毒DNA的末端具有高度保守的二核苷酸序列特征：5'TG...//...CA3'。对于禽和鼠C型逆转录病毒，二核苷酸序列位于未整合病毒DNA的LTR末端的两个脱氧核苷酸（通常为AA和TT）处（5' AATG...//...CATT3'）。尚未确定未整合的HIV-1线性DNA中延伸超过保守二核苷酸的末端脱氧核苷酸的数量和身份。然而，根据对逆转录病毒DNA合成的假定引物位点末端与保守的前病毒末端之间核苷酸序列的检查，推测它们在两端各由一个核苷酸组成（5'CTG...//...CAG3'）。我们利用聚合酶链反应（PCR）扩增代表从感染的T细胞中分离出的共价闭合环状HIV-1 DNA分子中存在的线性DNA连接末端的片段。将这些片段克隆，并确定几个独立克隆的LTR-LTR环连接点的核苷酸序列。根据结果，我们预测，与禽和鼠病毒一样，HIV-1线性DNA在保守二核苷酸之外还含有两个核苷酸：5'ACTG...//...CAGT3'。提出了这些末端起源和其他观察到的连接序列的模型。
