1KR7

Crystal structure of the nerve tissue mini-hemoglobin from the nemertean worm Cerebratulus lacteus

Summary for 1KR7

• Entry DOI: 10.2210/pdb1kr7/pdb
• Descriptor: Neural globin, SULFATE ION, ACETATE ION, ... (6 entities in total)
• Functional Keywords: nerve tissue, mini-hemoglobin, protein cavities, oxygen transport, oxygen storage-transport complex, oxygen storage/transport
• Biological source: Cerebratulus lacteus (milky ribbon-worm)
• Total number of polymer chains: 1
• Total formula weight: 12350.54

Authors

Pesce, A.,Nardini, M.,Dewilde, S.,Geuens, E.,Yamauchi, k.,Ascenzi, P.,Riggs, A.F.,Moens, L.,Bolognesi, M. (deposition date: 2002-01-09, release date: 2002-05-15, Last modification date: 2024-02-14)

Primary citation

Pesce, A.,Nardini, M.,Dewilde, S.,Geuens, E.,Yamauchi, k.,Ascenzi, P.,Riggs, A.F.,Moens, L.,Bolognesi, M.
The 109 residue nerve tissue minihemoglobin from Cerebratulus lacteus highlights striking structural plasticity of the alpha-helical globin fold
Structure, 10:725-735, 2002

PubMed Abstract: 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.

PubMed: 12015154
DOI: 10.1016/S0969-2126(02)00763-3

Experimental method

X-RAY DIFFRACTION (1.5 Å)