The contours are drawn at the 1 s level. This figure displays the region around the heme group. The iron ion is shown as a magenta-colored sphere. The distal His64 and proximal His93 are also labeled for clarity. The electron density of all the side chains in the figure including tryptophan, tyrosine and arginine are well defined.
Continuous density is observed for the main chain and bulges are seen for each oxygen atom.
These features all appear only with high quality data. Anomalous difference Patterson for myoglobin Figure 3. A 2F obs -F calc map for myoglobin showing the heme iron and the distal and proximal histidines. The results of the anomalous difference Fourier calculated for lysozyme are shown in Table 1 and Figure 4. The phase angles were calculated using PDB entry 1LZ8.