Figure 1.

Leucine Methyl Correlation Spectra of Rho130 and the EcoRV-DNA Complex. The methyl carbon region was sampled using 21 complex points in all experiments. The C_α resonances are broadened by unresolved coupling to the ¹⁵N amide nitrogen. The concentration of Rho130 was 1.0 mM and spectra were acquired at 30°C. In the case of the Rho130 sample, all four spectra were acquired under identical condition; 8 scans with the same spectral width (50 ppm) and number of points (40) in the non-methyl carbon dimension. The total acquisition time/experiment was 9 hours. In the rho130 spectra the one dimensional trace for the C_β peaks are divided by two and the trace for the C_γ peak was divided by four. The concentration of the EcoRV-DNA complex was 0.8 mM and the spectra were acquired at 35°C. In the case of EcoRV-DNA sample the spectral widths for the aliphatic carbons in the C_α C_β, C_γ, and the HMCM[CG]CBCA experiments were 20 ppm, 60 ppm, 20 ppm, and 50 ppm, respectively. These were sampled using 32, 40, 32, and 40 complex points, respectively. A total of 40, 16, 8, and 40 scans were acquired for the C_α, C_β, C_γ, and HMCM[CG]CBCA experiments, respectively, giving total acquisition times of 35.8, 17.92, 7.17, and 44.8 hours, respectively. The entire one dimensional trace for the HMCM[CG]CBCA experiment is multiplied by two. The increase in signal intensity for one residue from the EcoRV-DNA sample, after scaling for the total experimental time, is 2.0, 8.8, and 6.0 for the C_α, C_β, C_γ, experiments. These ratios are the lower limit because many correlations could not be observed in the HMCM[CG]CBCA experiment. The C_β experiment could have been run in ½ the time (8 scans), which would have given a total acquisition time for all three experiments of approximately 52 hours, i.e. not much longer than the entire HMCM[CG]CBCA experiment. Pulse sequences can be found in figure S1, along with additional guidelines for defining the acquisition time for the detection of non-methyl carbons.