BACKBONE H-1 AND N-15 RESONANCE ASSIGNMENTS OF THE N-TERMINAL SH3 DOMAIN OF DRK IN FOLDED AND UNFOLDED STATES USING ENHANCED-SENSITIVITY PULSED-FIELD GRADIENT NMR TECHNIQUES

The backbone H-1 and N-15 resonances of the N-terminal SH3 domain of the Drosophila signaling adapter protein, drk, have been assigned. This domain is in slow exchange on the NMR timescale between folded and predominantly unfolded states. Data were collected on both states simultaneously, on samples of the SH3 in near physiological buffer exhibiting an approximately 1:1 ratio of the two states. NMR methods which exploit the chemical shift dispersion of the N-15 resonances of unfolded states and pulsed held gradient water suppression approaches for avoiding saturation and dephasing of amide protons which rapidly exchange with solvent were utilized for the assignment.