Oldfield T J, Hubbard R E
Department of Chemistry, University of York, Heslington, U.K.
J Mol Graph. 1995 Feb;13(1):18-23, 52. doi: 10.1016/0263-7855(94)00006-e.
The program EXTRACT has been developed to extract accurate three-dimensional coordinates from published stereo alpha-carbon diagrams of protein structures. The approach is based on the display of scanned images of the left and right eye views of the diagram on a stereo-equipped workstation, allowing construction of a molecular model using the diagram as a guide. A number of structural checks assess the building, including probability maps derived for alpha-carbon geometry in protein structures. The procedure has also been extended to produce less accurate models from mono images.