Analysis of structural variability within two-dimensional biological crystals by a combination of patch averaging...

We study in this work the use of self organizing maps to analyze the structural variability that can be found along two-dimensional crystals of biological macromolecules. Small areas of the crystals, termed "patches" by previous researchers, are used to obtain local average images that are then used as the input of a Self Organizing Map. This procedure allows for a fast and accurate image classification. Multivariate Statistical Analysis is then used on the resulting code vectors producing a very condensed data representation. This methodology is applied to previously studied crystals of bacteriophage phi 29 p10 connector, finding a crystalline heterogeneity probably associated to multilayers in some areas of the crystal.