Publication
Title
Structural bases for heme binding and diatomic ligand recognition in truncated hemoglobins
Author
Abstract
Truncated hemoglobins (trHbs) are low-molecular-weight oxygen-binding heme-proteins distributed in eubacteria, cyanobacteria, unicellular eukaryotes, and in higher plants, constituting a distinct group within the hemoglobin (Hb) superfamily. TrHbs display amino acid sequences 2040 residues shorter than classical (non)vertebrate Hbs and myoglobins, to which they are scarcely related by sequence similarity. The trHb tertiary structure is based on a 2-on-2 á-helical sandwich, which represents a striking editing of the highly conserved 3-on-3 á-helical globin fold, achieved through deletion/truncation of á-helices and specific residue substitutions. Despite their minimal polypeptide chain span, trHbs display an inner tunnel/cavity system held to support ligand diffusion to/from the heme distal pocket, accumulation of heme ligands within the protein matrix, and/or multiligand reactions. Moreover, trHbs bind and effectively stabilize the heme and recognize diatomic ligands (i.e., O2, CO, NO, and cyanide), albeit with varying thermodynamic and kinetic parameters. Here, structural bases for heme binding and diatomic ligand recognition by trHbs are reviewed.
Language
English
Source (journal)
Journal of inorganic biochemistry. - New York, N.Y.
Publication
New York, N.Y. : 2005
ISSN
0162-0134
Volume/pages
99:1(2005), p. 97-109
ISI
000226555000009
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 10.04.2009
Last edited 31.10.2017
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