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Figure 1.
Figure 1 The MIg crystal structure and analysis of the MAM
domain. (A) Ribbon diagram of MIg. The MAM-Ig linker in the MAM
domain is highlighted in purple. Disulphide bonds (orange) and
the N-glycosylation sites (CPK) are presented as stick models.
The N- and C-termini are labelled. Inset shows the L-shape of
the molecule. Arrowhead indicates the largest crystal contact
site. (B) Comparisons of the MAM domain to two closely related
 -sandwich
structures. Ribbon diagrams are shown for comparisons of
secondary structures and molecular surfaces are shown to display
surface features of binding sites (marked by arrowheads).
Structurally equivalent regions (inter-C  distances
<3.0 Å) are shown in green and structurally distinct
regions are highlighted (blue in front of the -sandwich
and red at the back). In 1GUI:A, the blue loops demarcate the
carbohydrate-binding groove. In 1KGY:A, the red loops surround
the hydrophobic ephrinB2-binding pocket, which constitutes the
primary dimerization site; the blue loop forms the second
ephrinB2-binding site. Regions that are not superposable are
coloured in grey. Disulphide bonds are shown as orange sticks.
All three structures are shown from the same view upon
superimposition on MAM. (C) Structural details of the MAM L1 and
L2 loops. The L1 and L2 loops are depicted in stick
representation whereas the remainder of the MAM domain is shown
as a solid surface. Residues selected for mutagenesis studies
are highlighted with yellow carbon atoms. Phe68 (shown in pink)
corresponds to the F74S cancer-linked mutation in RPTP  .
As in panel A, linker residues are coloured in purple and
cysteines in orange. Asparagine residues providing sites for
N-linked glycosylation are distinguished by standard atom
colouring (carbon: white, nitrogen: blue, oxygen: red). This
figure was produced using Pymol (http://pymol.sourceforge.net/).
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