1MWB image
Deposition Date 2002-09-27
Release Date 2002-12-04
Last Version Date 2024-05-01
Entry Detail
PDB ID:
1MWB
Title:
Solution structure of the recombinant hemoglobin from the cyanobacterium Synechocystis sp. PCC 6803 in its hemichrome state
Biological Source:
Source Organism:
Method Details:
Experimental Method:
Conformers Calculated:
100
Conformers Submitted:
20
Selection Criteria:
structures with lowest energy and least restraint violations
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Cyanoglobin
Gene (Uniprot):glbN
Chain IDs:A
Chain Length:123
Number of Molecules:1
Biological Source:Synechocystis sp.
Ligand Molecules
Primary Citation
The Solution Structure of the Recombinant Hemoglobin from the Cyanobacterium Synechocystis sp. PCC 6803 in its Hemichrome State
J.MOL.BIOL. 324 1015 1029 (2002)
PMID: 12470956 DOI: 10.1016/S0022-2836(02)01093-8

Abstact

The product of the cyanobacterium Synechocystis sp. PCC 6803 gene slr2097 is a 123 amino acid polypeptide chain belonging to the truncated hemoglobin family. Recombinant, ferric heme-reconstituted Synechocystis sp. PCC 6803 hemoglobin displays bis-histidine coordination of the iron ion. In addition, this protein is capable of covalently attaching a reactive histidine to the heme 2-vinyl group. The structure of the protein in the low-spin ferric state with intact vinyl substituents was solved by NMR methods. It was found that the structure differs from that of known truncated hemoglobins primarily in the orientation of the E helix, which carries His46 (E10) as the distal ligand to the iron; the length and orientation of the F helix, which carries His70 (F8) as the proximal ligand to the iron; and the H-helix, which carries His117 (H16), the reactive histidine. Regions of enhanced flexibility include the short A helix, the loop connecting the E and F helices, and the last seven residues at the carboxy end. The structural data allowed for the rationalization of physical properties of the cyanobacterial protein, such as fast on-rate for small ligand binding, unstable apoprotein fold, and cross-linking ability. Comparison to the truncated hemoglobin from the green alga Chlamydomonas eugametos also suggested how the endogenous hexacoordination affected the structure.

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Primary Citation of related structures