I 
I 
Images (top and side views) of the x-ray crystal structure of a peptide corre- 
sponding to the leucine zipper of the yeast transcriptional activator GCN4, 
determined at 1.8 A resolution, in collaboration with Thomas Alber's research 
group at the University of Utah School of Medicine. The leucine zipper folds as a 
parallel coiled coil, with two helices supercoiled around each other. The cross- 
ing angle of the helices is about 20° . 
Research of Peter S. Kim. 
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