N -glycans from Paramecium bursaria chlorella virus MA-1D: Re-evaluation of the oligosaccharide common core structure
N -glycans from Paramecium bursaria chlorella virus MA-1D: Re-evaluation of the oligosaccharide common core structure
复制标题
来自草履虫小球藻病毒 MA-1D 的 N-聚糖：寡糖共同核心结构的重新评估
DOI：
10.1093/glycob/cwab113
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发表时间：
2021
期刊：
影响因子：
4.3
通讯作者：
De Castro, Cristina
中科院分区：
文献类型：
--
作者：
Speciale, Immacolata;Di Lorenzo, Flaviana;Notaro, Anna;Noel, Eric;Agarkova, Irina;Molinaro, Antonio;Van Etten, James L.;De Castro, Cristina
绿草履虫绿草履虫病毒MA-1D是侵染绿草履虫共生体变异小球藻NC 64 A株系的一种绿病毒。MA-1D基因组全长339-kb，编码CA。366种蛋白质和11种tRNA。与其他绿病毒一样，其主要衣壳蛋白（MCP）也被N-聚糖修饰，本文利用核磁共振波谱、基质辅助激光解吸电离飞行时间质谱（沿着）和MS/MS实验解析了MCP的结构。该分析确定了三种N-连接的寡糖，其不同之处在于三种单糖的非化学计量存在，其中最大的寡糖由八个残基组成，以高度分支的方式组织。这里描述的N-聚糖与其他绿病毒有几个共同的特征，除了它们缺乏一个远端木糖单位，这被认为是所有绿病毒保守核心区的一部分。MA-1D基因组的检查检测到一个基因与参考氯病毒PBCV-1和病毒NY-2A中推定的木糖基转移酶具有很强的同源性，尽管突变了一个过早的终止密码子。这一发现意味着我们需要重新考虑氯病毒中共同核心聚糖区域的基本特征。
Paramecium bursaria chlorella virus MA-1D is a chlorovirus that infectsChlorella variabilisstrain NC64A, a symbiont of the protozoanParamecium bursaria. MA-1D has a 339-kb genome encoding ca. 366 proteins and 11 tRNAs. Like other chloroviruses, its major capsid protein (MCP) is decorated withN-glycans, whose structures have been solved in this work by using nuclear magnetic spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry along with MS/MS experiments. This analysis identified three N-linked oligosaccharides that differ in the nonstoichiometric presence of three monosaccharides, with the largest oligosaccharide composed of eight residues organized in a highly branched fashion. TheN-glycans described here share several features with those of the other chloroviruses except that they lack a distal xylose unit that was believed to be part of a conserved core region for all the chloroviruses. Examination of the MA-1D genome detected a gene with strong homology to the putative xylosyltransferase in the reference chlorovirus PBCV-1 and in virus NY-2A, albeit mutated with a premature stop codon. This discovery means that we need to reconsider the essential features of the common core glycan region in the chloroviruses.