STRUCTURAL AND FUNCTIONAL STUDIES OF MAMMALIAN ENDOGENOUS RETROVIRAL SEQUENCES

白血病MCF13和非白血病MCFM111a整合酶基因的研究 比较了小鼠逆转录病毒的结构和生物学特性 活动。核苷酸序列分析表明，这两个 整合酶基因是不同的：有21个取代氨基酸 在MCF13和MCFM111a之间，其中4个影响亲水性 此外，MCF13小鼠体内还存在4种氨基酸 白血病病毒(MuLV)，在MCFM111AMuLV中缺失。要确定 整合酶基因之间的结构差异是否 影响整合酶的白血病与非白血病小鼠病毒 功能，我们分析了整合酶蛋白的体外活性。 生物系统。该方法测定了线性 病毒DNA，存在于感染细胞的细胞质提取液中，进入 Phi-x174靶DNA。结果表明，通过 导致白血病的MCF13是非白血病的两倍 MCFM111A。

The integrase genes of leukemogenic MCF13 and non-leukemogenic MCFM111A murine retroviruses were compared in their structure and biological activities. Nucleotide sequence analysis indicated that the two integrase genes were distinct: there were 21 substituted amino acids between MCF13 and MCFM111A, of which 4 affected the hydropathicity profile; in addition, 4 amino acids were present in MCF13 murine leukemia virus (MuLV) which were absent in MCFM111A MuLV. To determine whether the structural differences seen between the integrase genes of leukemogenic versus non-leukemogenic murine viruses affected integrase function, we analyzed the integrase protein activities using an in vitro biological system. This assay measured the incorporation of linear viral DNAs, present in cytoplasmic extracts from infected cells, into phi-X174 target DNA. The results indicated that integration by leukemogenic MCF13 was two-fold greater than by non-leukemogenic MCFM111A.