Figure 6.

Application of combinatorial ¹⁵N, ¹³C^α, ¹³C' labeling to LspA. An overlay of regions from ¹⁵N-HSQC spectra of a uniformly (black contours) and the three selectively labelled (blue, magenta and green contours) samples is shown at the top. Spectra analysis for the uniformly labelled protein is severely hampered by overlap, whereas almost all signals (exception: I107/I135 in the HN(CA) of sample 2) are well-resolved in the series of 2D triple-resonance spectra of the three samples of the combinatorial scheme. Signals that are missing in the H^α-filtered HN(CA) but present in the reference HN(CA), which indicates that they arise from ²H/¹⁵N-labelled amino acids preceded by 2-¹³C-labelled ones (see table S1 of the supplemental information), are highlighted by empty rectangles.