2gi9: Difference between revisions

Structural studies of uniformly labeled proteins by magic-angle spinning NMR spectroscopy have rapidly matured in recent years. Site-specific chemical shifts of several proteins have been assigned and structures determined from 2D or 3D data sets containing internuclear distance information. Here we demonstrate the application of a complementary technique for constraining protein backbone geometry using a site-resolved 3D dipolar-shift pulse sequence. The dipolar line shapes report on the relative orientations of 1H-15N[i] to 1H-15N[i+1] dipole vectors, constraining the torsion angles [i] and [i]. In addition, from the same 3D data set, several 1H-15N[i] to1H-15N[i+2] line shapes are extracted to constrain the torsion angles [i], [i], [i+1], and [i+1]. We report results for the majority of sites in the 56-residue 1 immunoglobulin binding domain of protein G (GB1), using 3D experiments at 600 MHz 1H frequency. Excellent agreement between the SSNMR results and a new 1.14 Å crystal structure illustrate the general potential of this technique for high-resolution structural refinement of solid proteins.

[[Category: Franks, W.T.]]

[[Category: Rienstra, C.M.]]

[[Category: Stellfox, S.A.]]

[[Category: Wylie, B.J.]]

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