Heregulin-a EGF domain

Once all the violations have been checked and some corrections have been made, the process of structure calculation starts all over again with a new, improved restraint list. It may take more than 20 cycles of calculation and reexamination of NMR data before the restraint violations are reduced to a minimum. The results of this process after 27 cycles of calculation are shown in Figure 12.37 for Heregulin-o EGF domain. The average of the 20 lowest energy structures is shown on the left side, and on the right side is the same structure rotated a bit about the vertical axis. The major /3-sheet (3-6,17-24,30-37) is clearly visible but is twisted in the 3D structure. A short a-helix is inserted between two strands of the /1-sheet, and a minor two-strand /i-shccl (39 11,46 19) is seen at the top. Residues 51-63 are disordered and are not shown in the figure. 

Jacobsen NE, Abadi N, Sliwkowski MX, Reilly D, Skelton NJ, Fairbrother WJ. High resolution solution structure of the EGF-like domain of heregulin-a. Biochemistry 1996 35 3402-3417. 

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