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Figure 3.
Figure 3 Active site of acid-  -glucosidase.
(A) The catalytic and glucone-binding site of acid- -glucosidase
(GlcCerase). The catalytic glutamates are shown as
ball-and-stick models and amino-acid residues nearby are shown
as sticks. Hydrogen bonds are shown as dashed lines for those
residues close enough to contact the glutamates. These residues
may be involved directly in catalysis or may modulate the
protonation states of the carboxyl groups. The others residues
are near the docked glucosyl moiety (see (B)), and these may
thus stabilize its interaction with GlcCerase. (B)
Three-dimensional surface diagram of GlcCerase (created using
PyMOL (http://www.pymol.org)), with a model of the docked
substrate (based on the coordinates of galactosylceramide
(Nyholm et al., 1990) and modified for GlcCer). Hydrophobic
residues (W, F, Y, L, I, V, M and C; Hopp & Woods, 1981) are
shown in blue, and the active-site residues (E235 and E340) in
yellow. GlcCer is shown in CPK format (carbon atoms in green,
and oxygen atoms in red).
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