1mlu

NITRIC OXIDE RECOMBINATION TO DOUBLE MUTANTS OF MYOGLOBIN: THE ROLE OF LIGAND DIFFUSION IN A FLUCTUATING HEME POCKET

spinqualitylabelsall models 1mlu, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1mlu is a 1 chain structure with sequence from Physeter catodon. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: CMO, HEM, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MYG_PHYMC Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles. 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 Picosecond recombination of nitric oxide to the double mutants of myoglobin, His64Gly-Val68Ala and His64Gly.Val68Ile, at E7 and E11, has been studied experimentally and by computation. It is shown that distal residues have a profound effect on NO recombination. Recombination in the mutants may be explained in terms of fluctuating free volume and structure of the heme pocket. The double mutants provide insight into the effects of free volume and steric hindrance on rates of ligand rebinding following photolysis. Water molecules of the first solvation shell replace surface residues deleted by mutation and can block apparent holes in the protein structure. Thus, water molecules extend the time required for ligands to escape significantly to a nanosecond time scale, which is much longer than would be expected for an open heme pocket. Both nearly exponential (G64A68) and markedly nonexponential (native and G64I68) kinetics are observed, a result at variance with expectation from the model of Petrich et al. [Petrich, J.W., Lambry, J.C., Kuczera, K., Karplus, M., Poyart, C., & Martin, J.L. (1991) Biochemistry 30, 3975-3987], which attributes nonexponential kinetics to proximal effects. Nitric oxide recombination to double mutants of myoglobin: role of ligand diffusion in a fluctuating heme pocket.,Carlson ML, Regan R, Elber R, Li H, Phillips GN Jr, Olson JS, Gibson QH Biochemistry. 1994 Sep 6;33(35):10597-606. PMID:8075059 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Myoglobin 3D structures

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