6Q6P

Antarctic fish cytoglobin 1 from D.mawsoni

Summary for 6Q6P

• Entry DOI: 10.2210/pdb6q6p/pdb
• Descriptor: Cytoglobin, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• Functional Keywords: cytoglobin, cold-adaptation, no dioxygenase, oxygen binding
• Biological source: Dissostichus mawsoni (Antarctic toothfish)
• Total number of polymer chains: 2
• Total formula weight: 41458.47

Authors

Giordano, D.,Pesce, A.,Vermeylen, S.,Abbruzzetti, S.,Nardini, M.,Marchesani, F.,Berghmans, H.,Seira, C.,Bruno, S.,Luque, F.J.,di Prisco, G.,Ascenzi, P.,Dewilde, S.,Bolognesi, M.,Viappiani, C.,Verde, C. (deposition date: 2018-12-11, release date: 2020-01-15, Last modification date: 2024-01-24)

Primary citation

Giordano, D.,Pesce, A.,Vermeylen, S.,Abbruzzetti, S.,Nardini, M.,Marchesani, F.,Berghmans, H.,Seira, C.,Bruno, S.,Javier Luque, F.,di Prisco, G.,Ascenzi, P.,Dewilde, S.,Bolognesi, M.,Viappiani, C.,Verde, C.
Structural and functional properties of Antarctic fish cytoglobins-1: Cold-reactivity in multi-ligand reactions.
Comput Struct Biotechnol J, 18:2132-2144, 2020

PubMed Abstract: While the functions of the recently discovered cytoglobin, ubiquitously expressed in vertebrate tissues, remain uncertain, Antarctic fish provide unparalleled models to study novel protein traits that may arise from cold adaptation. We report here the spectral, ligand-binding and enzymatic properties (peroxynitrite isomerization, nitrite-reductase activity) of cytoglobin-1 from two Antarctic fish, and and present the crystal structure of cytoglobin-1. The Antarctic cytoglobins-1 display high O affinity, scarcely compatible with an O-supply role, a slow rate constant for nitrite-reductase activity, and do not catalyze peroxynitrite isomerization. Compared with mesophilic orthologues, the cold-adapted cytoglobins favor binding of exogenous ligands to the -coordinated bis-histidyl species, a trait related to their higher rate constant for distal-His/heme-Fe dissociation relative to human cytoglobin. At the light of a remarkable 3D-structure conservation, the observed differences in ligand-binding kinetics may reflect Antarctic fish cytoglobin-1 specific features in the dynamics of the heme distal region and of protein matrix cavities, suggesting adaptation to functional requirements posed by the cold environment. Taken together, the biochemical and biophysical data presented suggest that in Antarctic fish, as in humans, cytoglobin-1 unlikely plays a role in O transport, rather it may be involved in processes such as NO detoxification.

PubMed: 32913582
DOI: 10.1016/j.csbj.2020.08.007

Experimental method

X-RAY DIFFRACTION (3 Å)