Chemistry Reference
In-Depth Information
(a)
(b)
(c)
(d)
(e)
FIGURE 13.22
Iron site of PCD complexed with substrate and substrate analogs. (a) PCD as isolated. (b) PCD complexed with 3-iodo-
4-hydroxybenzoate: because the large iodo group does not fit well in the active site, this is proposed to represent an early stage of subunit
binding. (c) 3-Fluoro-4-hydroxybenzoate: the smaller fluoro group results in a substrate that fits the active site better. (d) The enzyme
e
substrate
complex (PCA
ΒΌ
3,4-dihydroxybenzoate): Y447 removes the second substrate proton and is displaced as the chelated substrate complex is
formed. (e) Hypothetical model for the tertiary enzyme
e
substrate
e
dioxygen complex.
(From
Lange & Que, 1998
. Copyright 1998 with
permission from Elsevier.)
FIGURE 13.23
Active site coordination geometry of plant LOXs.
(Adopted from
Andreou & Feussner, 2009
.
)
