6hbi

SCAPHARCA DIMERIC HEMOGLOBIN, MUTANT T72V, DEOXY FORMSCAPHARCA DIMERIC HEMOGLOBIN, MUTANT T72V, DEOXY FORM

Structural highlights 6hbi is a 2 chain structure with sequence from Anadara inaequivalvis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.8Å Ligands: Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GLB1_ANAIN 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 cluster of interface ordered water molecules has been proposed to act as a key mediator of intersubunit communication in the homodimeric hemoglobin of Scapharca inaequivalvis. Mutations of Thr72 to Val and Ile, which lack the hydroxyl group to hydrogen bond the deoxy interface water molecules, result in sharply altered functional properties. We have determined the high resolution (1.6-1. 8 A) crystal structures of these two mutants in both the deoxygenated and CO-liganded states. These structures show minimal protein structural changes relative to the same native derivatives, despite greater than 40-fold increases in oxygen affinity. In the deoxy state of both mutants two water molecules at the periphery of the water cluster are lost, and the remaining cluster water molecules are destabilized. The CO-liganded structures show key differences between the two mutants including a more optimal interface packing involving Ile72 that acts to stabilize its high affinity (R) state. This additional stabilization allows rationalization of its lowered cooperativity within the context of a two-state model. These studies support a key role of ordered water in cooperative functioning and illustrate how subtle structural alterations can result in significantly altered functional properties in an allosteric molecule. Mutational destabilization of the critical interface water cluster in Scapharca dimeric hemoglobin: structural basis for altered allosteric activity.,Pardanani A, Gambacurta A, Ascoli F, Royer WE Jr J Mol Biol. 1998 Dec 4;284(3):729-39. PMID:9826511 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Hemoglobin 3D structures

spinqualitylabelsall models 6hbi, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image