Department of Biomedical Sciences and Veterinary Public Health, Section of Virology, The Swedish University of Agricultural Sciences, Ulls Väg 2B, SE-751 89, Uppsala, Sweden.
Virol J. 2012 Sep 19;9:211. doi: 10.1186/1743-422X-9-211.
Infectious bronchitis virus (IBV) is a Gammacoronavirus of the family Coronaviridae and is a causative agent of an economically important disease in poultry. The spike glycoprotein of IBV is essential for host cell attachment, neutralization, and is involved in the induction of protective immunity. Previously obtained sequence data of the spike gene of IBV QX-like and Massachusetts strains were subjected to bioinformatics analysis.
On analysis of potential phosphorylation sites, the Ser542 and Ser563 sites were not present in Massachusetts strains, while QX-like isolates did not have the Ser534 site. Massachusetts and QX-like strains showed different cleavage site motifs. The N-glycosylation sites ASN-XAA-SER/THR-55, 147, 200 and 545 were additionally present in QX-like strains. The leucine-rich repeat regions in Massachusetts strains consisted of stretches of 63 to 69 amino acids, while in the QX-like strains they contained 59 amino acids in length. An additional palmitoylation site was observed in CK/SWE/082066/2010 a QX-like strain. Primary structure data showed difference in the physical properties and hydrophobic nature of both genotypes. The comparison of secondary structures revealed no new structural domains in the genotypic variants. The phylogenetic analyses based on avian and mammalian coronaviruses showed the analysed IBV as closely related to turkey coronaviruses and distantly related to thrush and munia coronaviruses.
The study demonstrated that spike glycoprotein of the Massachusetts and the QX-like variants of IBV are molecularly distinct and that this may reflect in differences in the behavior of these viruses in vivo.
传染性支气管炎病毒（IBV）是冠状病毒科冠状病毒的一员，也是家禽中一种具有重要经济意义的疾病的病原体。IBV 的刺突糖蛋白对于宿主细胞附着、中和以及诱导保护性免疫至关重要。先前获得的 IBV QX 样株和马萨诸塞株的刺突基因序列数据进行了生物信息学分析。
在分析潜在的磷酸化位点时，马萨诸塞株中不存在 Ser542 和 Ser563 位点，而 QX 样株中不存在 Ser534 位点。马萨诸塞株和 QX 样株显示出不同的切割位点基序。QX 样株还存在 N-糖基化位点 ASN-XAA-SER/THR-55、147、200 和 545。马萨诸塞株中的富含亮氨酸重复区由 63 到 69 个氨基酸组成，而 QX 样株中则由 59 个氨基酸组成。在一株 QX 样株 CK/SWE/082066/2010 中还观察到一个额外的棕榈酰化位点。一级结构数据显示两种基因型在物理性质和疏水性方面存在差异。二级结构比较显示基因型变异体中没有新的结构域。基于禽源和哺乳动物冠状病毒的系统发育分析表明，所分析的 IBV 与火鸡冠状病毒密切相关，与画眉和文鸟冠状病毒关系较远。
该研究表明，马萨诸塞株和 QX 样株的 IBV 刺突糖蛋白在分子上是不同的，这可能反映了这些病毒在体内行为的差异。
