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.