Figure 4 - full size

Figure 4.
Figure 4. Omit electron density for bound substrate and product molecules contoured at 2.5s (stereo view). All complexes were prepared by soaking. (a) Product complex with bound CMP and 2C-methyl- Image -erythritol 2,4-cyclodiphosphate (data set Prod). (b) Substrate complex with bound 4-diphosphocytidyl-2C-methyl- Image -erythritol 2-phosphate and zinc removed with EDTA; the green ball represents the zinc position in the active enzyme (data set CDP-MEP). (c) Complex with 4-diphosphocytidyl-2C-methyl- Image -erythritol (data set CDP-ME). (d) Complex with MgCDP; the Mg ion bridges the a and b-phosphate groups of CDP (data set MgCDP).