Overcoming the problems associated with poor spectra quality of the protein kinase Byr2 using residual dipolar couplings

For the Ras-binding domain of the protein kinase Byr2, only a limited numbe r of NOE contacts could be initially assigned unambiguously, as the quality of the NOESY spectra was too poor. However, the use of residual H-1-N-15 d ipolar couplings in the beginning of the structure determination process al lows to overcome this problem. We used a three-step recipe for this procedu re. A previously unknown structure could be calculated reasonably well with only a limited number of unambiguously assigned NOE contacts.