Figure 3.
Fig. 3. Ribbon diagrams of (from left) I-antithrombin (15),
pentasaccharide-complexed I-antithrombin, and [1]-antitrypsin
(32). The pentasaccharide activation of I-antithrombin is seen
to involve^ a closing of the A-sheet (magenta), an extension
(blue) of helix D (yellow), and an expulsion of residues P[14]
(green sphere) and^ P[15] (black sphere) of the reactive site
loop (red). The reactive^ loop of both antithrombin molecules is
constrained by the dimer contact (see Fig. 2a) of the -pleated
P[3]-P[8] (ribboned arrow). An indication of the likely free
conformation, with exposure of^ the P[1] reactive center (shown
as a ball-stick model), is provided^ by the optimal inhibitory
conformation of the reactive loop present in [1]-antitrypsin
(32).
[1]-antitrypsin
(32). The pentasaccharide activation of I-antithrombin is seen
to involve^ a closing of the A-sheet (magenta), an extension
(blue) of helix D (yellow), and an expulsion of residues P[14]
(green sphere) and^ P[15] (black sphere) of the reactive site
loop (red). The reactive^ loop of both antithrombin molecules is
constrained by the dimer contact (see Fig. 2a) of the 
-pleated
P[3]-P[8] (ribboned arrow). An indication of the likely free
conformation, with exposure of^ the P[1] reactive center (shown
as a ball-stick model), is provided^ by the optimal inhibitory
conformation of the reactive loop present in