Elder J H, Mullins J I
J Virol. 1983 Jun;46(3):871-80. doi: 10.1128/JVI.46.3.871-880.1983.
The nucleotide sequence of the envelope gene and the adjacent 3' long terminal repeat (LTR) of Gardner-Arnstein feline leukemia virus of subgroup B (GA-FeLV-B) has been determined. Comparison of the derived amino acid sequence of the gp70-p15E polyprotein to those of several previously reported murine retroviruses revealed striking homologies between GA-FeLV-B gp70 and the gp70 of a Moloney virus-derived mink cell focus-forming virus. These homologies were located within the substituted (presumably xenotropic) portion of the mink cell focus-forming virus envelope gene and comprised amino acid sequences not present in three ecotropic virus gp70s. In addition, areas of insertions and deletions, in general, were the same between GA-FeLV-B and Moloney mink cell focus-forming virus, although the sizes of the insertions and deletions differed. Homologies between GA-FeLV-B and mink cell focus-forming virus gp70s is functionally significant in that they both possess expanded host ranges, a property dictated by gp70. The amino acid sequence of FeLV-B contains 12 Asn-X-Ser/Thr sequences, indicating 12 possible sites of N-linked glycosylation as compared with 7 or 8 for its murine counterparts. Comparison of the 3' LTR of GA-FeLV-B to AKR and Moloney virus LTRs revealed extensive conservation in several regions including the "CCAAT" and Goldberg-Hogness (TATA) boxes thought to be involved in promotion of transcription and in the repeat region of the LTR. The inverted repeats that flanked the LTR of GA-FeLV-B were identical to the murine inverted repeats, but were one base longer than the latter. The region of U3 corresponding to the approximately 75-nucleotide "enhancer sequence" is present in GA-FeLV-B, but contains deletions relative to AKR and Moloney virus and is not repeated. An interesting pallindrome in the repeat region immediately 3' to the U3 region was noted in all the LTRs, but was particularly pronounced in GA-FeLV-B. Possible roles for this structure are discussed.
已确定B亚组加德纳 - 阿恩斯坦猫白血病病毒（GA - FeLV - B）包膜基因的核苷酸序列以及相邻的3'长末端重复序列（LTR）。将gp70 - p15E多蛋白推导的氨基酸序列与几种先前报道的鼠逆转录病毒的序列进行比较，结果显示GA - FeLV - B gp70与莫洛尼病毒衍生的水貂细胞灶形成病毒的gp70之间存在显著同源性。这些同源性位于水貂细胞灶形成病毒包膜基因的取代（可能是异嗜性）部分内，并且包含三种嗜亲性病毒gp70中不存在的氨基酸序列。此外，尽管插入和缺失的大小不同，但GA - FeLV - B与莫洛尼水貂细胞灶形成病毒之间的插入和缺失区域总体上是相同的。GA - FeLV - B与水貂细胞灶形成病毒gp70之间的同源性在功能上具有重要意义，因为它们都具有扩大的宿主范围，这是由gp70决定的一种特性。FeLV - B的氨基酸序列包含12个Asn - X - Ser/Thr序列，表明有12个可能的N - 连接糖基化位点，而其鼠类对应物有7个或8个。将GA - FeLV - B的3'LTR与AKR和莫洛尼病毒的LTR进行比较，发现在几个区域存在广泛的保守性，包括被认为参与转录促进的“CCAAT”和戈德堡 - 霍格尼斯（TATA）框以及LTR的重复区域。GA - FeLV - B LTR侧翼的反向重复序列与鼠类反向重复序列相同，但比后者长一个碱基。GA - FeLV - B中存在对应于约75个核苷酸“增强子序列”的U3区域，但相对于AKR和莫洛尼病毒含有缺失且不重复。在所有LTR中，在紧接U3区域3'的重复区域中都注意到一个有趣的回文结构，在GA - FeLV - B中尤为明显。讨论了这种结构可能的作用。
