Department of Agricultural Sciences, University of Napoli, 80055 Portici, Italy;
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2032.
Proc Natl Acad Sci U S A. 2018 Jan 2;115(1):E44-E52. doi: 10.1073/pnas.1613432115. Epub 2017 Dec 18.
The glycans of the major capsid protein (Vp54) of chlorella virus (PBCV-1) were recently described and found to be unusual. This prompted a reexamination of the previously reported Vp54 X-ray structure. A detailed description of the complete glycoprotein was achieved by combining crystallographic data with molecular modeling. The crystallographic data identified most of the monosaccharides located close to the protein backbone, but failed to detect those further from the glycosylation sites. Molecular modeling complemented this model by adding the missing monosaccharides and examined the conformational preference of the whole molecule, alone or within the crystallographic environment. Thus, combining X-ray crystallography with carbohydrate molecular modeling resulted in determining the complete glycosylated structure of a glycoprotein. In this case, it is the chlorovirus PBCV-1 major capsid protein.
最近描述了绿藻病毒（PBCV-1）主要衣壳蛋白（Vp54）的聚糖，发现它们不同寻常。这促使我们重新检查之前报道的 Vp54 X 射线结构。通过将晶体学数据与分子建模相结合，实现了对完整糖蛋白的详细描述。晶体学数据确定了靠近蛋白质骨架的大多数单糖，但未能检测到离糖基化位点更远的单糖。分子建模通过添加缺失的单糖来补充该模型，并检查整个分子在晶体环境中的单独或组合时的构象偏好。因此，将 X 射线晶体学与碳水化合物分子建模相结合，确定了糖蛋白的完整糖基化结构。在这种情况下，它是绿藻病毒 PBCV-1 的主要衣壳蛋白。
