Figure 3

Agreement between chemical shift- and ensemble-derived secondary structure populations of E7. Secondary structure populations of E7 derived from backbone ¹⁵N, ¹³C′, ¹³C^α, ¹³C^β, ¹H^N chemical shifts using the δ2D method (bars). For comparison, secondary structure populations are also obtained using an alternative method, by back-calculating them from the RAM ensemble; they are depicted by the dotted blue (α-helix), red (β-sheet) and green (PPII) lines (the remaining population, which is random coil, is not depicted here for clarity). The stretches with missing bars are due to missing chemical shift assignments in the NMR spectra and mainly concern the folded part of the E7C domain. The average structure of the E7C domain calculated from the RAM ensemble is depicted in the inset and shows partial population of β strands, in agreement with the secondary structural population.