2vee
From Proteopedia
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, resolution 2.60Å | |||||||
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Sites: | , , , , , , and | ||||||
Ligands: | |||||||
Related: | 2VEB
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Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
Coordinates: | save as pdb, mmCIF, xml |
STRUCTURE OF PROTOGLOBIN FROM METHANOSARCINA ACETIVORANS C2A
Overview
The structural adaptability of the globin fold has been highlighted by the recent discovery of the 2-on-2 haemoglobins, of neuroglobin and cytoglobin. Protoglobin from Methanosarcina acetivorans C2A-a strictly anaerobic methanogenic Archaea-is, to the best of our knowledge, the latest entry adding new variability and functional complexity to the haemoglobin (Hb) superfamily. Here, we report the 1.3 A crystal structure of oxygenated M. acetivorans protoglobin, together with the first insight into its ligand-binding properties. We show that, contrary to all known globins, protoglobin-specific loops and an amino-terminal extension completely bury the haem within the protein matrix. Access of O(2), CO and NO to the haem is granted by the protoglobin-specific apolar tunnels reaching the haem distal site from locations at the B/G and B/E helix interfaces. Functionally, M. acetivorans dimeric protoglobin shows a selectivity ratio for O(2)/CO binding to the haem that favours O(2) ligation and anticooperativity in ligand binding. Both properties are exceptional within the Hb superfamily.
About this Structure
2VEE is a Single protein structure of sequence from Methanosarcina acetivorans. Full crystallographic information is available from OCA.
Reference
Archaeal protoglobin structure indicates new ligand diffusion paths and modulation of haem-reactivity., Nardini M, Pesce A, Thijs L, Saito JA, Dewilde S, Alam M, Ascenzi P, Coletta M, Ciaccio C, Moens L, Bolognesi M, EMBO Rep. 2008 Feb;9(2):157-63. Epub 2008 Jan 11. PMID:18188182
Page seeded by OCA on Mon Mar 31 05:11:13 2008
Categories: Methanosarcina acetivorans | Single protein | Alam, M. | Ascenzi, P. | Bolognesi, M. | Ciaccio, C. | Coletta, M. | Dewilde, S. | Moens, L. | Nardini, M. | Pesce, A. | Saito, J A. | Thijs, L. | Archaea protein | Hemoprotein structure | Methanogenesis | Protein matrix tunnel | Protoglobin | Transport protein