1s6a
From Proteopedia
|
The X-ray structure of the cyanobacteria Synechocystis hemoglobin "cyanoglobin" with azide ligand
Overview
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 Structure
1S6A is a Single protein structure of sequence from Synechocystis sp. with , and as ligands. Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Thu Feb 21 14:58:27 2008
Categories: Single protein | Synechocystis sp. | Hargrove, M S. | Hoy, J A. | III, J T.Trent. | Kundu, S. | AZI | FLC | HEM | 2 on 2 helical fold | Cyanobacteria | Globin | Heme | Hemoglobin | Hexacoordinate | Iron | Oxygen binding | Truncated
