1do7

CARBONMONOXY-MYOGLOBIN (MUTANT L29W) REBINDING STRUCTURE AFTER PHOTOLYSIS AT T< 180K

spinqualitylabelsall models 1do7, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1do7 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 1.85Å Ligands: CMO, FME, GLC, HEM, PRD_900006, 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 Myoglobin, a small globular haem protein that binds gaseous ligands such as O2, CO and NO reversibly at the haem iron, serves as a model for studying structural and dynamic aspects of protein reactions. Time-resolved spectroscopic measurements after photodissociation of the ligand revealed a complex ligand-binding reaction with multiple kinetic intermediates, resulting from protein relaxation and movements of the ligand within the protein. To observe the structural changes induced by ligand dissociation, we have carried out X-ray crystallographic investigations of carbon monoxy-myoglobin (MbCO mutant L29W) crystals illuminated below and above 180 K, complemented by time-resolved infrared spectroscopy of CO rebinding. Here we show that below 180 K photodissociated ligands migrate to specific sites within an internal cavity--the distal haem pocket--of an essentially immobilized, frozen protein, from where they subsequently rebind by thermally activated barrier crossing. Upon photodissociation above 180 K, ligands escape from the distal pocket, aided by protein fluctuations that transiently open exit channels. We recover most of the ligands in a cavity on the opposite side of the haem group. Ligand binding and conformational motions in myoglobin.,Ostermann A, Waschipky R, Parak FG, Nienhaus GU Nature. 2000 Mar 9;404(6774):205-8. PMID:10724176 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Myoglobin 3D structures

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