Figure 1.
(a) Final refined 1.25-Å-resolution 2F[o] – F[c]
electron density for the binding site in the type A crystal
complex, calculated using SIGMAA^31 weighted map coefficients
generated by REFMAC^32 is contoured at 0.25 e^- Å^-3
(equivalent to the s.d. of the final map). Refined structure is
shown as sticks colored by atom type (green, Cd44 carbons; cyan,
HA carbons; blue, nitrogen; red, oxygen; yellow, sulfur).
Individual sugar rings in the bound HA[8] oligosaccharide are
numbered from the nonreducing end. (b) A ribbon diagram of mouse
Cd44 (type B complex), with secondary structure identified using
the DSSP algorithm^33. Pink, -helices;
white, loops; green and gold, -sheets
I and II, respectively; cyan, bound HA. (c) Surface
representation of the HA-binding site in the type B crystal
complex. The shallow HA-binding groove is shown as molecular
surface. Gold, supplementary lobe formed from N- and C-terminal
Link extensions; cyan, HA. Selected residues marking the
boundaries of the groove are labeled. The type A crystal form
shows similar features but lacks the lower platform for the HA
interaction provided by reorientation of Arg45.
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
Nat Struct Biol
(2007,
14,
234-239)
copyright 2007.
-helices;
white, loops; green and gold, 
-sheets
I and II, respectively; cyan, bound HA. (c) Surface
representation of the HA-binding site in the type B crystal
complex. The shallow HA-binding groove is shown as molecular
surface. Gold, supplementary lobe formed from N- and C-terminal
Link extensions; cyan, HA. Selected residues marking the
boundaries of the groove are labeled. The type A crystal form
shows similar features but lacks the lower platform for the HA
interaction provided by reorientation of Arg45.