Pesce, A. (2008) Crystal structure of archeal protoglobin: Novel ligand diffusion paths to the heme. Il nuovo cimento C, 31 (4). pp. 539-546. ISSN 1826-9885
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Abstract
The protein structural adaptability of the globin fold has been highlighted by the recent discovery of 2-on-2 hemoglobins, of neuroglobin, cytoglobin, and the characterization of their three-dimensional structures. Protoglobin from Methanosarcina acetivorans C2A is the latest entry in the hemoglobin superfamily, adding to it new structural variability and functional complexity. The 1.3˚A crystal structure of oxygenated M. acetivorans protoglobin shows that, contrary to all known globins, protoglobin-specific loops and a N-terminal extension completely bury the heme within the protein matrix. Access of diatomic ligands (such as O2, CO, and NO) to the heme is however granted by protoglobin-specific apolar tunnels that reach the heme distal site from entry sites at the B/G and B/E helix interfaces. Functionally, M. acetivorans dimeric protoglobin displays a selectivity ratio for O2/CO binding to the heme that favours O2 ligation, a property that is exceptional within the hemoglobin superfamily.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | X-ray diffraction ; Other topics in structure of solids and liquids; crystallography ; Molecular crystals ; Tertiary structure |
| Subjects: | 500 Scienze naturali e Matematica > 530 Fisica |
| Depositing User: | Marina Spanti |
| Date Deposited: | 23 Mar 2020 16:53 |
| Last Modified: | 23 Mar 2020 16:53 |
| URI: | http://eprints.bice.rm.cnr.it/id/eprint/16391 |
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