STRUCTURAL AND FUNCTIONAL STUDIES OF MAMMALIAN ENDOGENOUS RETROVIRAL SEQUENCES

致白血病MCF 13和非致白血病MCF 111 A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， 整合酶基因不同，有21个氨基酸被替换 MCF 13和MCFM 111 A之间的差异，其中4个影响了疏水性 此外，MCF 13小鼠中存在4种氨基酸 白血病病毒（MuLV），其在MCFM 111 A MuLV中不存在。 以确定 整合酶基因之间的结构差异是否 致白血病与非致白血病鼠病毒影响整合酶 功能，我们分析了整合酶蛋白的活性，使用体外 生物系统。 该测定法测量了线性 病毒DNA，存在于感染细胞的细胞质提取物中， phi-X174靶DNA。 结果表明， 致白血病的MCF 13是非致白血病的MCF 13的两倍。 MCFM 111A。

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.