VISUALIZATION OF 3-DIMENSIONAL DENSITY MAPS RECONSTRUCTED FROM CRYOELECTRON MICROGRAPHS OF VIRAL CAPSIDS

Full evaluation of three-dimensional density maps calculated from cryo electron micrographs of complex supramolecular structures requires tha t the maps be sifted by a variety of complementary visualization techn iques. We present here a primer for a number of such techniques in cur rent widespread use, including surface rendering; serial sections; sim ulated motion; and real-time manipulation of tiled surfaces displayed on an advanced workstation, The principles on which these techniques o perate are briefly reviewed, as are their advantages and limitations, with emphasis on the requirements for visual representation of viral c apsid structures. These methods are illustrated in application to a de nsity map of herpes simplex virus type 1 (HSV-1) capsid at 24 Angstrom resolution, which reveals more detailed information than heretofore c oncerning the inner surface of the icosahedral capsid shell and the 15 0-Angstrom-long channels that pass through each of the 162 capsomers. (C) 1996 Academic Press, Inc.