EMXtalOrg: an EM tilt data organization and processing system

The EMXtalOrg software package organizes and processes electron microscope (EM) data from indexed images of tilted two-dimensional (2D) protein crystals. The package, which is freely available, was written to facilitate the processing of amplitude and phase (aph) data from 2D EM projections into three-dimensional (3D) reconstructions. The suite takes as input contrast transfer function corrected aph files and generates lattice line data to yield HKL files which can be output for viewing 3D structures with existing data visualization programs. Additionally, the package offers a number of other processing features, and provides a convenient graphical interface for several image processing programs devoted to the analysis of 2D crystals. The package is written in the Python scripting language using the Tcl/ Tk toolkit for the graphical user interface, making it portable and easy to modify by the user. The package provides an integrated environment to simplify the process of obtaining 3D structures from 2D crystals.