2a4t

Crystal structure of spin labeled T4 Lysozyme (V131R7)Crystal structure of spin labeled T4 Lysozyme (V131R7)

Structural highlights 2a4t is a 1 chain structure with sequence from Escherichia virus T4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.7Å Ligands: , , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ENLYS_BPT4 Endolysin with lysozyme activity that degrades host peptidoglycans and participates with the holin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles. Once the holin has permeabilized the host cell membrane, the endolysin can reach the periplasm and break down the peptidoglycan layer. 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 High resolution (1.43-1.8 A) crystal structures and the corresponding electron paramagnetic resonance (EPR) spectra were determined for T4 lysozyme derivatives with a disulfide-linked nitroxide side chain [-CH(2)-S-S-CH(2)-(3-[2,2,5,5-tetramethyl pyrroline-1-oxyl]) identical with R1] substituted at solvent-exposed helix surface sites (Lys65, Arg80, Arg119) or a tertiary contact site (Val75). In each case, electron density is clearly resolved for the disulfide group, revealing distinct rotamers of the side chain, defined by the dihedral angles X(1) and X(2). The electron density associated with the nitroxide ring in the different mutants is inversely correlated with its mobility determined from the EPR spectrum. Residue 80R1 assumes a single g(+)()g(+)() conformation (Chi(1) = 286, X(2) = 294). Residue 119R1 has two EPR spectral components, apparently corresponding to two rotamers, one similar to that for 80R1 and the other in a tg(-)() conformation (Chi(1) = 175, X(2) = 54). The latter state is apparently stabilized by interaction of the disulfide with a Gln at i + 4, a situation also observed at 65R1. R1 residues at helix surface site 65 and tertiary contact site 75 make intra- as well as intermolecular contacts in the crystal and serve to identify the kind of molecular interactions possible for the R1 side chain. A single conformation of the entire 75R1 side chain is stabilized by a variety of interactions with the nitroxide ring, including hydrophobic contacts and two unconventional C-H.O hydrogen bonds, one in which the nitroxide acts as a donor (with tyrosine) and the other in which it acts as an acceptor (with phenylalanine). The interactions revealed in these structures provide an important link between the dynamics of the R1 side chain, reflected in the EPR spectrum, and local protein structure. A library of such interactions will provide a basis for the quantitative interpretation of EPR spectra in terms of protein structure and dynamics. Crystal structures of spin labeled T4 lysozyme mutants: implications for the interpretation of EPR spectra in terms of structure.,Langen R, Oh KJ, Cascio D, Hubbell WL Biochemistry. 2000 Jul 25;39(29):8396-405. PMID:010913245 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Lysozyme 3D structures

spinqualitylabelsall models 2a4t, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image