The 109 residue nerve tissue minihemoglobin from Cerebratulus lacteus highlights striking structural plasticity of the α-helical globin fold
Articolo
Data di Pubblicazione:
2002
Citazione:
The 109 residue nerve tissue minihemoglobin from Cerebratulus lacteus highlights striking structural plasticity of the α-helical globin fold / A. Pesce, M. Nardini, S. Dewilde, E. Geuens, K. Yamauchi, P. Ascenzi, A.F. Riggs, L. Moens, M. Bolognesi. - In: STRUCTURE. - ISSN 0969-2126. - 10:5(2002 May), pp. 725-735. [10.1016/S0969-2126(02)00763-3]
Abstract:
A very short hemoglobin (CerHb; 109 amino acids) binds O2 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 Å 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 O2 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.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
globin fold plasticity; nerve tissue minihemoglobin; oxygen binding; oxygenated hemoglobin; protein cavities; X-ray crystallography
Elenco autori:
A. Pesce, M. Nardini, S. Dewilde, E. Geuens, K. Yamauchi, P. Ascenzi, A.F. Riggs, L. Moens, M. Bolognesi
Link alla scheda completa: