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 , and 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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