Figure 9 Experimental electron-density map of trypsin calculated using anomalous differences to 3.5  Å and the SAD phases from the Ca2+, six S super-atoms and two S atoms. (a) The electron-density maps of the -sheet (Gln50-Ser54, Ser84-Val90, Ile103-Lys109); (b) the electron-density map of residues Asp102-Lys107; (c) electron density of the helix (Tyr234-Asn245). Only main-chain atoms are displayed for (a) and (c).

© International Union of Crystallography 2003