Facilitated assignment of large protein NMR signals with covariance sequential spectra using spectral derivatives.

Nuclear magnetic resonance (NMR) studies of larger proteins are hampered by difficulties in assigning NMR resonances. Human intervention is typically required to identify NMR signals in 3D spectra, and subsequent procedures depend on the accuracy of this so-called peak picking. We present a method that provides sequential connectivities through correlation maps constructed with covariance NMR, bypassing the need for preliminary peak picking.

NMR methods for structural studies of large monomeric and multimeric proteins.

NMR structural studies of large monomeric and multimeric proteins face distinct challenges. In large monomeric proteins, the common occurrence of frequency degeneracies between residues impedes unambiguous assignment of NMR signals. To overcome this barrier, nonuniform sampling (NUS) is used to measure spectra with optimal resolution within reasonable time, new correlation maps resolve previous impasses in assignment strategies, and novel selective methyl labeling schemes provide additional structural probes without cluttering NMR spectra.

The molecular basis for substrate specificity of the nuclear NIPP1:PP1 holoenzyme.

Regulation of protein phosphatase 1 (PP1) is controlled by a diverse array of regulatory proteins. However, how these proteins direct PP1 specificity is not well understood. More than one-third of the nuclear pool of PP1 forms a holoenzyme with the nuclear inhibitor of PP1, NIPP1, to regulate chromatin remodeling, among other essential biological functions.