Figure 16
Unmodelled PTMs in the PDB. Density for protein modifications may be present but left unmodelled. (a) Lys84 has positive difference density surrounding the side-chain amino group (PDB entry 2jc7; Santillana et al., 2007). (b) Addition of a carboxyl group to the NZ atom of Lys84 [using Coot (Emsley et al., 2010) and AceDRG (Long et al., 2017)], followed by refinement with REFMAC (Murshudov et al., 2011). 2mFo − DFc electron density is shown in blue at 1σ for the residue. Positive difference density (mFo − DFc) is shown in green contoured to 4σ and clipped within 4 Å of Lys84. The rest of the protein chain is represented by a yellow ribbon model. |