Relatedness of baculovirus and gypsy retrotransposon envelope proteins
Relatedness of baculovirus and gypsy retrotransposon envelope proteins
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DOI：
10.1186/1471-2148-1-1
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发表时间：
2001-02-19
影响因子：
3.4
通讯作者：
Karplus, P. Andrew
中科院分区：
文献类型：
--
作者：
Rohrmann, George F.;Karplus, P. Andrew
背景：目前的证据表明，鳞翅目杆状病毒可根据其包膜融合蛋白分为两个系统发育组。一组使用 gp64，一种低 pH 依赖性的包膜融合蛋白，而另一组则使用与 gp64 无关的蛋白质家族（例如舞毒蛾核多角体病毒中的 LD130），但它也是低 pH 依赖性的。对 LD130 蛋白家族成员的数据库搜索经常记录到与吉普赛类昆虫逆转录病毒样转座元件的包膜蛋白具有显着水平的同源性。在本报告中，分析了这两类包膜蛋白之间同源性的显着性。 结果：使用 Z 分数评估比对分数的显着性，Z 分数是通过将观察到的比对分数与其中一个序列对其序列进行 100 次随机改组后获得的比对分数分布进行比较来计算的。与大多数吉普赛包膜蛋白相比，这些分析得出 LD130 家族成员的 Z 分数 > 9。此外，除了显着水平的序列同源性以及预测的信号序列和跨膜结构域的存在之外，该家族的成员还包含可能的弗林蛋白酶切割基序、该位点下游的保守基序、预测的卷曲螺旋结构域以及保守的半胱氨酸残基模式。结论：这些分析提供了来自一组昆虫逆转录病毒样元件的包膜蛋白和 杆状病毒蛋白家族，包括低 pH 依赖性包膜融合蛋白。吉普赛逆转录因子从昆虫转座到杆状病毒基因组的能力表明了这些病毒家族之间这种蛋白质交换的途径。
Background: Current evidence suggests that lepidopteran baculoviruses may be divided into two phylogenetic groups based on their envelope fusion proteins. One group utilizes gp64, a low pH-dependent envelope fusion protein, whereas the other employs a protein family (e.g. LD130 in the Lymantria dispar nucleopolyhedrovirus) unrelated to gp64, but that is also low pH-dependent. Database searches with members of the LD130 protein family often record significant levels of homology to envelope proteins from a number of insect retrovirus-like transposable elements of the gypsy class. In this report, the significance of the homology between these two types of envelope proteins is analyzed.Results: The significance of the alignment scores was evaluated using Z-scores that were calculated by comparing the observed alignment score to the distribution of scores obtained for alignments after one of the sequences was subjected to 100 random shuffles of its sequence. These analyses resulted in Z-scores of > 9 for members of the LD130 family when compared to most gypsy envelope proteins. Furthermore, in addition to significant levels of sequence homology and the presence of predicted signal sequences and transmembrane domains, members of this family contain a possible a furin cleavage motif, a conserved motif downstream of this site, predicted coiled-coil domains, and a pattern of conserved cysteine residues.Conclusions: These analyses provide a link between envelope proteins from a group of insect retrovirus-like elements and a baculovirus protein family that includes low-pH-dependent envelope fusion proteins. The ability of gypsy retroelements to transpose from insect into baculovirus genomes suggests a pathway for the exchange of this protein between these viral families.