1kr7
From Proteopedia
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Coordinates: | save as pdb, mmCIF, xml |
Crystal structure of the nerve tissue mini-hemoglobin from the nemertean worm Cerebratulus lacteus
Overview
A very short hemoglobin (CerHb; 109 amino acids) binds O(2) cooperatively in the nerve tissue of the nemertean worm Cerebratulus lacteus to sustain neural activity during anoxia. Sequence analysis suggests that CerHb tertiary structure may be unique among the known globin fold evolutionary variants. The X-ray structure of oxygenated CerHb (R factor 15.3%, at 1.5 A resolution) displays deletion of the globin N-terminal A helix, an extended GH region, a very short H helix, and heme solvent shielding based on specific aromatic residues. The heme-bound O(2) is stabilized by hydrogen bonds to the distal TyrB10-GlnE7 pair. Ligand access to heme may take place through a wide protein matrix tunnel connecting the distal site to a surface cleft located between the E and H helices.
About this Structure
1KR7 is a Single protein structure of sequence from Cerebratulus lacteus. Full crystallographic information is available from OCA.
Reference
The 109 residue nerve tissue minihemoglobin from Cerebratulus lacteus highlights striking structural plasticity of the alpha-helical globin fold., Pesce A, Nardini M, Dewilde S, Geuens E, Yamauchi K, Ascenzi P, Riggs AF, Moens L, Bolognesi M, Structure. 2002 May;10(5):725-35. PMID:12015154
Page seeded by OCA on Thu Mar 20 12:21:08 2008
Categories: Cerebratulus lacteus | Single protein | Ascenzi, P. | Bolognesi, M. | Dewilde, S. | Geuens, E. | Moens, L. | Nardini, M. | Pesce, A. | Riggs, A F. | Yamauchi, k. | ACT | HEM | OXY | SO4 | Mini-hemoglobin | Nerve tissue | Oxygen transport | Protein cavity