Figure 3.
Figure 3. Interactions of the sequestered oxoG base with other
components in the active site of the borohydride-trapped
complex. a, Ball-and-stick representation of the X-ray
structure. Color scheme is as in Fig. 2. b, Schematic depiction
of the oxoG triangulated in position over the three atoms that
are involved in acid/base chemistry during the -lyase
cascade (N ,
O4' and C2'). Hydrogen bonding interactions are denoted by
dashes. Dots indicate the distance between N9 and C2'. Note the
distances between the N9 of oxoG and the O4' of the substrate
sugar and the N of
Lys249 in (a), indicative of hydrogen-bonding interactions. Also
note the disposition of the proS and proR protons (denoted S and
R, respectively) on C2' with respect to N9 and O8. The helix
capping interaction between the side chain of Asp268 and the N
terminus of helix M
is clearly visible in (a).
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
Nat Struct Biol
(2003,
10,
204-211)
copyright 2003.
-lyase
cascade (N 
,
O4' and C2'). Hydrogen bonding interactions are denoted by
dashes. Dots indicate the distance between N9 and C2'. Note the
distances between the N9 of oxoG and the O4' of the substrate
sugar and the N 
M
is clearly visible in (a).