1s6a
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The X-ray structure of the cyanobacteria Synechocystis hemoglobin "cyanoglobin" with azide ligand
OverviewOverview
The crystal structures of cyanide and azide-bound forms of the truncated, hemoglobin from Synechocystis are presented at 1.8 angstroms resolution. A, comparison with the structure of the endogenously liganded protein reveals, a conformational shift unprecedented in hemoglobins, and provides the, first picture of a hexacoordinate hemoglobin in both the bis-histidyl and, the exogenously coordinated states. The structural changes between the, different conformations are confined to two regions of the protein; the B, helix, and the E helix, including the EF loop. A molecular "hinge", controlling movement of the E helix is observed in the EF loop, which is, composed of three principal structural elements: Arg64, the, heme-d-propionate, and a three-residue extension of the F helix., Additional features of the structural transition between the two protein, conformations are discussed as they relate to the complex ligand-binding, behavior observed in hexacoordinate hemoglobins, and the potential, physiological function of this class of proteins.
About this StructureAbout this Structure
1S6A is a Single protein structure of sequence from Synechocystis sp. with FLC, AZI and HEM as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Crystallographic analysis of synechocystis cyanoglobin reveals the structural changes accompanying ligand binding in a hexacoordinate hemoglobin., Trent JT 3rd, Kundu S, Hoy JA, Hargrove MS, J Mol Biol. 2004 Aug 20;341(4):1097-108. PMID:15289104
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