1s6a
The X-ray structure of the cyanobacteria Synechocystis hemoglobin "cyanoglobin" with azide ligandThe X-ray structure of the cyanobacteria Synechocystis hemoglobin "cyanoglobin" with azide ligand
Structural highlights
FunctionTRHBN_SYNY3 Forms a very stable complex with oxygen. The oxygen dissociation rate is 0.011 s(-1). 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 PubMedThe 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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