Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
J Gen Virol. 2011 Feb;92(Pt 2):445-52. doi: 10.1099/vir.0.026476-0. Epub 2010 Nov 10.
Sobemoviruses possess a viral genome-linked protein (VPg) attached to the 5' end of viral RNA. VPg is processed from the viral polyprotein. In the current study, Cocksfoot mottle virus (CfMV) and Rice yellow mottle virus (RYMV) VPgs were purified from virions and analysed by mass spectrometry. The cleavage sites in the polyprotein and thereof the termini of VPg were experimentally proven. The lengths of the mature VPgs were determined to be 78 and 79 aa residues, respectively. The amino acid residues covalently linked to RNA in the two VPgs were, surprisingly, not conserved; it is a tyrosine at position 5 of CfMV VPg and serine at position 1 of RYMV VPg. Phosphorylations were identified in CfMV and RYMV VPgs with two positionally similar locations T20/S14 and S71/S72, respectively. RYMV VPg contains an additional phosphorylation site at S41.
Sobemoviruses 拥有一种连接在病毒 RNA 5' 端的病毒基因组连接蛋白（VPg）。VPg 由病毒多蛋白加工而来。在本研究中，从病毒粒子中纯化了雀麦花叶病毒（CfMV）和水稻黄花叶病毒（RYMV）的 VPg，并通过质谱分析进行了分析。通过实验证明了多蛋白中的切割位点及其 VPg 的末端。成熟 VPg 的长度分别确定为 78 和 79 个氨基酸残基。令人惊讶的是，这两个 VPg 中与 RNA 共价连接的氨基酸残基并不保守；CfMV VPg 的第 5 位是酪氨酸，而 RYMV VPg 的第 1 位是丝氨酸。在 CfMV 和 RYMV VPg 中分别鉴定到了两个位置相似的磷酸化位点 T20/S14 和 S71/S72。RYMV VPg 还含有一个额外的磷酸化位点 S41。
