2veb

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Revision as of 08:56, 23 January 2008

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spinqualitylabelsall models 2veb, resolution 1.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

HIGH RESOLUTION 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

2VEB is a Single protein structure of sequence from Methanosarcina acetivorans with , , and as ligands. Known structural/functional Sites: , , , and . 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 Jan 11;. PMID:18188182

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