Kronenberg S, Kleinschmidt J A, Böttcher B
Deutsches Krebsforschungszentrum, Forschungsschwerpunkt Angewandte Tumorvirologie, Im Neuenheimer Feld 242, D-69120 Heidelberg, Germany.
EMBO Rep. 2001 Nov;2(11):997-1002. doi: 10.1093/embo-reports/kve234.
Adeno-associated virus type 2 empty capsids are composed of three proteins, VP1, VP2 and VP3, which have relative molecular masses of 87, 72 and 62 kDa, respectively, and differ in their N-terminal amino acid sequences. They have a likely molar ratio of 1:1:8 and occupy symmetrical equivalent positions in an icosahedrally arranged protein shell. We have investigated empty capsids of adeno-associated virus type 2 by electron cryo-microscopy and icosahedral image reconstruction. The three-dimensional map at 1.05 nm resolution showed sets of three elongated spikes surrounding the three-fold symmetry axes and narrow empty channels at the five-fold axes. The inside of the capsid superimposed with the previously determined structure of the canine parvovirus (Q. Xie and M.S. Chapman, 1996, J. Mol. Biol., 264, 497-520), whereas the outer surface showed clear discrepancies. Globular structures at the inner surface of the capsid at the two-fold symmetry axes were identified as possible positions for the N-terminal extensions of VP1 and VP2.
2型腺相关病毒空衣壳由三种蛋白质VP1、VP2和VP3组成，它们的相对分子质量分别为87 kDa、72 kDa和62 kDa，且N端氨基酸序列不同。它们的摩尔比可能为1:1:8，并在二十面体排列的蛋白质外壳中占据对称等效位置。我们通过电子冷冻显微镜和二十面体图像重建研究了2型腺相关病毒的空衣壳。分辨率为1.05 nm的三维图谱显示，围绕三重对称轴有三组细长的刺突，在五重轴处有狭窄的空通道。衣壳内部与先前确定的犬细小病毒结构重叠（Q. Xie和M.S. Chapman，1996年，《分子生物学杂志》，264卷，497 - 520页），而外表面则存在明显差异。在二重对称轴处衣壳内表面的球状结构被确定为VP1和VP2 N端延伸的可能位置。
