Figure 7.

Anomalous electron density at site 1. Enlarged images of the structural model at site 1 with an overlay of anomalous electron density (magenta mesh) with 2F _o − F _c electron density (blue mesh). In all maps, the anomalous density is contoured at 5σ to emphasize the differences in signal for manganese (a), iron (b) and zinc (c). In (a) and (b) there is additional anomalous density from a methionine S atom that does not appear for the same S atom in the zinc data. These images were collected using data from the M9–Zn experiment.