Signal peptide cleavage prediction for GP5 of all Arteriviruses.

Representative N-terminal sequences (1–50) of GP5 of each member of the Arterivirus genus: EAV, equine arteritis virus (strain Bucyrus, GenBank accession number [ABI64076.1], PRRSV: porcine reproductive and respiratory syndrome virus (type 1/European, strain Lelystad [AAA46278.1] and type 2/North American, strain VR 2332 [AAD12129.1]), LDV: murine lactate dehydrogenase-elevating virus (NCBI reference sequence [NP_042577.1]), SHFV: simian hemorrhagic fever virus (NCBI reference sequence [NP_203550.1]). The predicted signal peptide (in small letters) and the “D value” for the most probable cleavage site (vertical bar) according to bioinformatics prediction with SignalP 4.0 are indicated. (D is a measure for cleavage likelihood, threshold: 0.45– note that the signal peptide of SHFV is predicted not to be cleaved.) Potential N-glycosylation sites are highlighted in bold (proven experimentally for LDV [57]). For PRRSV type 2, two signal peptide cleavage sites are possible (indicated with vertical bar). The decoy epitope (VLAN, in italics) would be absent in the mature protein if cleavage is performed at the most likely site (A31|S32).动脉炎病毒属（Arterivirus genus）各成员GP5蛋白的N端1~50位代表性序列如下：马动脉炎病毒（equine arteritis virus，株系Bucyrus，GenBank登录号ABI64076.1）；猪繁殖与呼吸综合征病毒（porcine reproductive and respiratory syndrome virus，简称PRRSV：1型/欧洲株系Lelystad[登录号AAA46278.1]及2型/北美株系VR 2332[登录号AAD12129.1]）；鼠乳酸脱氢酶升高病毒（murine lactate dehydrogenase-elevating virus，简称LDV，NCBI参考序列NP_042577.1）；猴出血热病毒（simian hemorrhagic fever virus，简称SHFV，NCBI参考序列NP_203550.1）。 经SignalP 4.0生物信息学预测得到的信号肽（以小写字母标注）以及对应最可能切割位点的“D值”已标注，切割位点以竖线标示。其中D值用于衡量信号肽切割可能性，阈值为0.45——需注意，SHFV的信号肽经预测无法被切割。 潜在的N-糖基化位点（N-glycosylation sites）以粗体标注，LDV的该位点已通过实验验证[57]。针对PRRSV 2型，存在两个可能的信号肽切割位点（以竖线标示）。若在最可能的切割位点（A31|S32）处完成切割，成熟蛋白中将不存在该诱饵表位（decoy epitope，VLAN，以斜体标注）。