Figure 2
Stereoview of the PGA fragment bound to subunit A. An Fo − Fc OMIT difference density map is shown, where Fo are the observed and Fc are the calculated structure factors derived from the crystallographic model excluding the contributions from PGA atoms. The map is contoured at 3σ (blue chicken wire) and PGA is shown as a stick model with C positions coloured yellow, O positions red and N positions blue. The protein is depicted in a green ribbon format. The D-glutamic acid units are numbered 1–5. |