Table 4: Mean Distances (Standard Deviations in Parentheses) Between Equivalent Atoms in Different Secondary Structures in NMR and X-Ray Models After Cα Based Superposition. After superposition Cα-Cα distances for different types of secondary structure elements were calculated. Superpositions were made with CE, DALI, and PROFIT. When the PDB entry corresponding to a NMR structure contains several models, values were averaged. The values reported in the table are thus averages of averages.
| Secondary Structure |
CE (Å) |
DALI (Å) |
PROFIT (Å) |
| Helix mean(std) distance |
1.50(0.02) |
1.80(0.02) |
2.55(0.08) |
| Sheet mean(std) distance |
1.08(0.02) |
1.40(0.02) |
1.39(0.03) |
| Loop mean(std) distance |
1.79(0.03) |
2.04(0.02) |
2.58(0.07) |