Figure 2.
Fig. 2. Cbl interactions with bovine TC (monoclinic crystal
form). (A) Stereoview of the F[o] - F[c] omit electron density
map at 2.0-Å resolution around the coordination of His-175
N to the Co ion of Cbl
(contour level 3 ). Some solvent water
molecules are shown as red spheres, one of which forms a H-bond
to His-175 N . The Co ion (magenta)
is axially coordinated by the imidazole N at a distance of 2.13
Å (above the corrin plane) and by the
dimethylbenzimidazole nitrogen N3B at 2.09 Å. (B) Scheme
of polar interactions. H-bonds are shown as dotted lines (red,
to residues in the -domain; blue, to
residues in the -domain; green,
solvent-mediated interactions). The main or side chain is
indicated for residues in direct contact with Cbl, whereas dots
indicate residues linked to Cbl via solvent molecules (11 H[2]O
and a Cl- ion from NaCl salt). The same scheme of direct
contacts is observed in human TC (to translate from bovine to
human TC numbering, see Fig. 3).
to the Co ion of Cbl
(contour level 3 
). Some solvent water
molecules are shown as red spheres, one of which forms a H-bond
to His-175 N 
. The Co ion (magenta)
is axially coordinated by the imidazole N 
-domain; blue, to
residues in the 
-domain; green,
solvent-mediated interactions). The main or side chain is
indicated for residues in direct contact with Cbl, whereas dots
indicate residues linked to Cbl via solvent molecules (11 H[2]O
and a Cl- ion from NaCl salt). The same scheme of direct
contacts is observed in human TC (to translate from bovine to
human TC numbering, see Fig. 3).