3dr9 | pdb_00003dr9

Increased Distal Histidine Conformational Flexibility in the Deoxy Form of Dehaloperoxidase from Amphitrite ornata

spinqualitylabelsall models 3dr9, resolution 1.26Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3dr9 is a 2 chain structure with sequence from Amphitrite ornata. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.26Å Ligands: HEM, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q9NAV8_9ANNE 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 The enzyme dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata is a heme protein which has a globin fold but can function as both a hemoglobin and a peroxidase. As a peroxidase, DHP is capable of converting 2,4,6-trihalophenols to the corresponding 2,6-dihaloquinones in the presence of hydrogen peroxide. As a hemoglobin, DHP cycles between the oxy and deoxy states as it reversibly binds oxygen for storage. Here, it is reported that the distal histidine, His55, exhibits conformational flexibility in the deoxy form and is consequently observed in two solvent-exposed conformations more than 9.5 A away from the heme. These conformations are analogous to the open conformation of sperm whale myoglobin. The heme iron in deoxy ferrous DHP is five-coordinate and has an out-of-plane displacement of 0.25 A from the heme plane. The observation of five-coordinate heme iron with His55 in a remote solvent-exposed conformation is consistent with the hypothesis that His55 interacts with heme iron ligands through hydrogen bonding in the closed conformation. Since His55 is also displaced by the binding of 4-iodophenol in an internal pocket, these results provide new insight into the correlation between heme iron ligation, molecular binding in the distal pocket and the conformation of the distal histidine in DHP. Distal histidine conformational flexibility in dehaloperoxidase from Amphitrite ornata.,Chen Z, de Serrano V, Betts L, Franzen S Acta Crystallogr D Biol Crystallogr. 2009 Jan;65(Pt 1):34-40. Epub 2008, Dec 18. PMID:19153464 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Dehaloperoxidase 3D structures

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