Figure 2

B factors (as a measure of local backbone mobility, on the y -axys) of C-alpha atoms for the free (gray) and the gp120-complexed (red) CD4 protein (C-alpha residue numbering is on the x-axis, according to UniProtKB/Swiss-Prot P01730).The first Ig-like V-type (residues 26 -- 125) and the second Ig-like C2-type 1 (residues 126 -- 203) were included in this analysis. Data were calculated from PDB files 3CD4 and 2NXY for free and complexed CD4, respectively. The third and forth domains were not considered due to the expected influence on B factors of these portions of the molecule by physiological CD4 dimerization.