Baker T S, Caspar D L
Ultramicroscopy. 1984;13(1-2):137-51. doi: 10.1016/0304-3991(84)90064-0.
Polymorphic assemblies of polyoma virus capsomeres that have been called "hexamer" tubes (because the morphological units are six-coordinated) are, in fact, built of pentamers, as is the icosahedrally symmetric T = 7d virus capsid. We have established the pentameric form of the capsomeres in the "hexamer" tubes by analysis of low-irradiation micrographs. Methods for generating computer image models with adjustable parameters have been developed to fit micrographs of negatively stained, flattened tubes. The image model has been refined to define the packing arrangement and substructure of the pentametric capsomeres in the superimposed top and bottom layers of the tube and to represent the differential flattening, lateral distortion and staining of the two sides. Information about the structure that is not directly accessible by conventional image filtering methods can be obtained by image modeling methods.
多瘤病毒衣壳粒的多态性聚集体被称为“六聚体”管（因为形态学单位是六配位的），实际上是由五聚体构成的，二十面体对称的T = 7d病毒衣壳也是如此。我们通过分析低辐射显微照片确定了“六聚体”管中衣壳粒的五聚体形式。已经开发出具有可调参数的生成计算机图像模型的方法，以拟合负染色扁平管的显微照片。图像模型已经得到完善，以定义管的叠加顶层和底层中五聚体衣壳粒的堆积排列和亚结构，并表示两侧的差异扁平化、横向变形和染色情况。通过图像建模方法可以获得常规图像滤波方法无法直接获取的有关结构的信息。
