Averages of glutamine synthetase molecules as obtained with various skin and electron dose conditions

Averaged projections of individual glutamine synthetase molecules have been obtained by using electron microscopy and image processing. The methodology of correlation averaging under low dose conditions is described in detail. Because of their low signal-to-noise ratio, images made under low dose conditions cannot be directly interpreted in terms of high resolution features. Computer averaging of these images reveals a division of the subunit projection into two domains whose sizes agree with results of Lei et al [2] limited proteolysis experiments.