2cuu

Crystal structure of spin labeled T4 Lysozyme (V131R1)

spinqualitylabelsall models 2cuu, resolution 1.75Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2cuu is a 1 chain structure with sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: AZI, CL, HED, MTN Activity: Lysozyme, with EC number 3.2.1.17 Resources: FirstGlance, OCA, RCSB, PDBsum Function [LYS_BPT4] Helps to release the mature phage particles from the cell wall by breaking down the peptidoglycan. 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 PubMed A disulfide-linked nitroxide side chain (R1) used in site-directed spin labeling of proteins often exhibits an EPR spectrum characteristic of a weakly ordered z-axis anisotropic motion at topographically diverse surface sites, including those on helices, loops and edge strands of beta-sheets. To elucidate the origin of this motion, the first crystal structures of R1 that display simple z-axis anisotropic motion at solvent-exposed helical sites (131 and 151) and a loop site (82) in T4 lysozyme have been determined. Structures of 131R1 and 151R1 determined at cryogenic or ambient temperature reveal an intraresidue C(alpha)--H...S(delta) interaction that immobilizes the disulfide group, consistent with a model in which the internal motions of R1 are dominated by rotations about the two terminal bonds (Columbus, Kalai, Jeko, Hideg, and Hubbell, Biochemistry 2001;40:3828-3846). Remarkably, the 131R1 side chain populates two rotamers equally, but the EPR spectrum reflects a single dominant dynamic population, showing that the two rotamers have similar internal motion determined by the common disulfide-backbone interaction. The anisotropic motion for loop residue 82R1 is also accounted for by a common disulfide-backbone interaction, showing that the interaction does not require a specific secondary structure. If the above observations prove to be general, then significant variations in order and rate for R1 at noninteracting solvent-exposed helical and loop sites can be assigned to backbone motion because the internal motion is essentially constant. Structural origin of weakly ordered nitroxide motion in spin-labeled proteins.,Fleissner MR, Cascio D, Hubbell WL Protein Sci. 2009 May;18(5):893-908. PMID:19384990 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Lysozyme 3D structures

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