Download MendeleyCytoglobin Cavities
De Sanctis, D., Dewilde, S., Pesce, A., Moens, L., Ascenzi, P., Hankeln, T., Burmester, T., Bolognesi, M.(2004) Biochem Biophys Res Commun 316: 1217
- PubMed: 15044115
- DOI: https://doi.org/10.1016/j.bbrc.2004.03.007
- Primary Citation of Related Structures:
1URY, 1UX9 - PubMed Abstract:
Cytoglobin is the fourth recognized globin type, almost ubiquitously distributed in human tissues; its function is still poorly understood. Cytoglobin displays a core region of about 150 residues, structurally related to hemoglobin and myoglobin, and two extra segments, about 20 residues each, at the N- and C-termini. The core region hosts a large apolar cavity, held to provide a ligand diffusion pathway to/from the heme, and/or ligand temporary docking sites. Here we report the crystal structure (2.4A resolution, R-factor 19.1%) of a human cytoglobin mutant bearing the CysB2(38) --> Ser and CysE9(83) --> Ser substitutions (CYGB*), treated under pressurized xenon. Three Xe atoms bind to the heme distal site region of CYGB* mapping the protein matrix apolar cavity. Despite the conserved globin fold, the cavity found in CYGB* is structured differently from those recognized to play a functional role in myoglobin, neuroglobin, truncated hemoglobins, and Cerebratulus lacteus mini-hemoglobin.
Organizational Affiliation:
Department of Physics-INFM and Centre for Excellence in Biomedical Research, University of Genova, Via Dodecaneso 33, Genoa I-16146, Italy.
