1mwb
From Proteopedia
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Solution structure of the recombinant hemoglobin from the cyanobacterium Synechocystis sp. PCC 6803 in its hemichrome state
Overview
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.
About this Structure
1MWB is a Single protein structure of sequence from Synechocystis sp. with HEM as ligand. Full crystallographic information is available from OCA.
Reference
The solution structure of the recombinant hemoglobin from the cyanobacterium Synechocystis sp. PCC 6803 in its hemichrome state., Falzone CJ, Christie Vu B, Scott NL, Lecomte JT, J Mol Biol. 2002 Dec 13;324(5):1015-29. PMID:12470956
Page seeded by OCA on Thu Nov 8 13:13:40 2007
