Figure 1
N—Cα—C bond angles vary systematically with conformation. (a) Average N—Cα—C backbone bond angles for well populated regions of the Ramachandran plot (≥10 observations in a 5 × 5° bin) are displayed with coloring as indicated in the sidebar. The values were derived for general amino-acid residues (all but Gly, Pro, and residues preceding Pro) from a database of ca 19 000 residues in protein structures determined at 1.0 Å resolution or better. (b) The standard deviations of the distributions in each region of the Ramachandran plot are shown as in (a). The smoothed plots of the data were produced in Matlab using an adaptive kernel regression with a global κ of 25. |