2rlz
From Proteopedia
Solid-State MAS NMR structure of the dimer Crh
Structural highlights
FunctionCRH_BACSU Along with seryl-phosphorylated HPr, phosphorylated Crh is implicated in carbon catabolite repression (CCR) of levanase, inositol dehydrogenase, and beta-xylosidase. Exerts its effect on CCR by interacting with CcpA.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn a wide variety of proteins, insolubility presents a challenge to structural biology, as X-ray crystallography and liquid-state NMR are unsuitable. Indeed, no general approach is available as of today for studying the three-dimensional structures of membrane proteins and protein fibrils. We here demonstrate, at the example of the microcrystalline model protein Crh, how high-resolution 3D structures can be derived from magic-angle spinning solid-state NMR distance restraints for fully labeled protein samples. First, we show that proton-mediated rare-spin correlation spectra, as well as carbon-13 spin diffusion experiments, provide enough short, medium, and long-range structural restraints to obtain high-resolution structures of this 2 x 10.4 kDa dimeric protein. Nevertheless, the large number of 13C/15N spins present in this protein, combined with solid-state NMR line widths of about 0.5-1 ppm, induces substantial ambiguities in resonance assignments, preventing 3D structure determination by using distance restraints uniquely assigned on the basis of their chemical shifts. In the second part, we thus demonstrate that an automated iterative assignment algorithm implemented in a dedicated solid-state NMR version of the program ARIA permits to resolve the majority of ambiguities and to calculate a de novo 3D structure from highly ambiguous solid-state NMR data, using a unique fully labeled protein sample. We present, using distance restraints obtained through the iterative assignment process, as well as dihedral angle restraints predicted from chemical shifts, the 3D structure of the fully labeled Crh dimer refined at a root-mean-square deviation of 1.33 A. 3D structure determination of the Crh protein from highly ambiguous solid-state NMR restraints.,Loquet A, Bardiaux B, Gardiennet C, Blanchet C, Baldus M, Nilges M, Malliavin T, Bockmann A J Am Chem Soc. 2008 Mar 19;130(11):3579-89. Epub 2008 Feb 20. PMID:18284240[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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