Water molecules amine oxidase active site

FIGURE 12. Structure of the E coli Amine Oxidase active site in die catalytically-active crystal form. Copper coordination and hydrogen bonds are shown by dashed lines and dotted lines respectively. Also shown are TPQ in its active conformation, die active site base Asp383, the conserved Tyr369 and a water molecule (W2) observed in most crystal forms of amine oxidases from various organisms. The equatorial water (We) is shown in parendieses since it is labile, variable in position and is absent in some crystal forms. 

Fig. 20. a Active site of E. coli amine oxidase. The polypeptide backbone is shown as a continuous coil, colored white for subunit A and grey for subunit B. Conserved residues are shown in all-atom representation, and the copper is shown as a green van der Waals dot surface. The position of TPQ in crystal form I is illustrated in green, coordinated to the copper. The precise location and orientation of the TPQ ring are not completely determined at the resolution of the current studies of crystal form II, and its general location is indicated by a yellow phenyl ring, close to the putative catalytic base Asp 383 (red). In crystal form II, TPQ is not a copper ligand, and the copper coordination is completed by two water molecules, shown in yellow (with permission from [28])... 

The most recent crystallographic study discloses the structure of the methylamine oxidase from the yeast Hansenula polymorpha [31], which shows an integrated network of water molecules providing electron transfer from topa quinone to copper and other important features such as the channel for oxygen entry and hydrogen peroxide release. The role of the active site aspartate base (Asp319) in the aminotransferase mechanism of the copper amine oxidase from H. polymorpha has been probed by site-directed mutagenesis [141]. It has been demonstrated by several... 

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