Figure 6.

Structure of the MT1 domain active site. A, conformational changes in the MT1 domain active site. The surface view shows the MT1 domain active site of AtPMT1 with bound pCho and SAH (stick models). The positions of the α1-helix and β1e–α7 loop of the AtPMT2·SAH complex are shown as a ribbon diagram (green). The positions of the α1- and α2-helices and β1e–α7 loop of the AtPMT1·SAH·pCho complex are shown in ribbon diagram (green). B, MT1 domain SAH/SAM-binding site in the AtPMT1·SAH·pCho complex structure. Secondary structure is shown in white with side chains contacting SAH as stick models. C, stereo view of the MT1 domain phosphobase-binding site in the AtPMT1·SAH·pCho complex structure. The view shows secondary structure as white ribbon diagrams with side chains contacting pCho as stick models.