Figure 3.
Fig. 3. Aglycone recognition and binding in -glycosidases
as revealed by DIMBOAGlc-, DIMBOA-, and dhurrin-Glu1E191D
inactive mutant complexes. (A) Closeup view of the active site
of Glu1, showing the catalytic glutamates E191 and E406 (red),
the four residues (F198, F205, W378, and F466) forming the
aglycone-binding pocket (light blue), and the additional
residues (A467 and Y473) that are probably important for
aglycone recognition (light green). (B) Glu1E191D with bound
DIMBOAGlc. The glycone moiety is in blue, whereas the aglycone
is in atom-type colors. The bulky aryl group is sandwiched
between W378 on one side and F198, F205, and F466 on the other.
(C) Same as B but with bound DIMBOA, showing a slightly
different orientation than DIMBOA in DIMBOAGlc, which is
constrained by the glycosidic linkage. (D) Same as B but with
bound dhurrin. The aglycone moiety of the inhibitor dhurrin is
in the same position as the aglycone of the natural substrate.
Figs. 3. and 4 were produced with TURBO-FRODO (38).
-glycosidases
as revealed by DIMBOAGlc-, DIMBOA-, and dhurrin-Glu1E191D
inactive mutant complexes. (A) Closeup view of the active site
of Glu1, showing the catalytic glutamates E191 and E406 (red),
the four residues (F198, F205, W378, and F466) forming the
aglycone-binding pocket (light blue), and the additional
residues (A467 and Y473) that are probably important for
aglycone recognition (light green). (B) Glu1E191D with bound
DIMBOAGlc. The glycone moiety is in blue, whereas the aglycone
is in atom-type colors. The bulky aryl group is sandwiched
between W378 on one side and F198, F205, and F466 on the other.
(C) Same as B but with bound DIMBOA, showing a slightly
different orientation than DIMBOA in DIMBOAGlc, which is
constrained by the glycosidic linkage. (D) Same as B but with
bound dhurrin. The aglycone moiety of the inhibitor dhurrin is
in the same position as the aglycone of the natural substrate.
Figs. 3. and 4 were produced with TURBO-FRODO (38).