1qi9
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1qi9.jpg|left|200px]] | + | [[Image:1qi9.jpg|left|200px]] |
| - | + | ||
| - | '''X-RAY SIRAS STRUCTURE DETERMINATION OF A VANADIUM-DEPENDENT HALOPEROXIDASE FROM ASCOPHYLLUM NODOSUM AT 2.0 A RESOLUTION''' | + | {{Structure |
| + | |PDB= 1qi9 |SIZE=350|CAPTION= <scene name='initialview01'>1qi9</scene>, resolution 2.05Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=VO4:VANADATE+ION'>VO4</scene> and <scene name='pdbligand=IOD:IODIDE ION'>IOD</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Chloride_peroxidase Chloride peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.10 1.11.1.10] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''X-RAY SIRAS STRUCTURE DETERMINATION OF A VANADIUM-DEPENDENT HALOPEROXIDASE FROM ASCOPHYLLUM NODOSUM AT 2.0 A RESOLUTION''' | ||
| + | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1QI9 is a [ | + | 1QI9 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Ascophyllum_nodosum Ascophyllum nodosum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QI9 OCA]. |
==Reference== | ==Reference== | ||
| - | X-ray structure determination of a vanadium-dependent haloperoxidase from Ascophyllum nodosum at 2.0 A resolution., Weyand M, Hecht H, Kiess M, Liaud M, Vilter H, Schomburg D, J Mol Biol. 1999 Oct 29;293(3):595-611. PMID:[http:// | + | X-ray structure determination of a vanadium-dependent haloperoxidase from Ascophyllum nodosum at 2.0 A resolution., Weyand M, Hecht H, Kiess M, Liaud M, Vilter H, Schomburg D, J Mol Biol. 1999 Oct 29;293(3):595-611. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10543953 10543953] |
[[Category: Ascophyllum nodosum]] | [[Category: Ascophyllum nodosum]] | ||
[[Category: Chloride peroxidase]] | [[Category: Chloride peroxidase]] | ||
| Line 26: | Line 35: | ||
[[Category: vanadium]] | [[Category: vanadium]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 13:37:55 2008'' |
Revision as of 11:37, 20 March 2008
| |||||||
| , resolution 2.05Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | Chloride peroxidase, with EC number 1.11.1.10 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
X-RAY SIRAS STRUCTURE DETERMINATION OF A VANADIUM-DEPENDENT HALOPEROXIDASE FROM ASCOPHYLLUM NODOSUM AT 2.0 A RESOLUTION
Overview
The homo-dimeric structure of a vanadium-dependent haloperoxidase (V-BPO) from the brown alga Ascophyllum nodosum (EC 1.1.11.X) has been solved by single isomorphous replacement anomalous scattering (SIRAS) X-ray crystallography at 2.0 A resolution (PDB accession code 1QI9), using two heavy-atom datasets of a tungstate derivative measured at two different wavelengths. The protein sequence (SwissProt entry code P81701) of V-BPO was established by combining results from protein and DNA sequencing, and electron density interpretation. The enzyme has nearly an all-helical structure, with two four-helix bundles and only three small beta-sheets. The holoenzyme contains trigonal-bipyramidal coordinated vanadium atoms at its two active centres. Structural similarity to the only other structurally characterized vanadium-dependent chloroperoxidase (V-CPO) from Curvularia inaequalis exists in the vicinity of the active site and to a lesser extent in the central four-helix bundle. Despite the low sequence and structural similarity between V-BPO and V-CPO, the vanadium binding centres are highly conserved on the N-terminal side of an alpha-helix and include the proposed catalytic histidine residue (His418(V-BPO)/His404(V-CPO)). The V-BPO structure contains, in addition, a second histidine near the active site (His411(V-BPO)), which can alter the redox potential of the catalytically active VO2-O2 species by protonation/deprotonation reactions. Specific binding sites for the organic substrates, like indoles and monochlordimedone, or for halide ions are not visible in the V-BPO structure. A reaction mechanism for the enzymatic oxidation of halides is discussed, based on the present structural, spectroscopic and biochemical knowledge of vanadium-dependent haloperoxidases, explaining the observed enzymatic differences between both enzymes.
About this Structure
1QI9 is a Single protein structure of sequence from Ascophyllum nodosum. Full crystallographic information is available from OCA.
Reference
X-ray structure determination of a vanadium-dependent haloperoxidase from Ascophyllum nodosum at 2.0 A resolution., Weyand M, Hecht H, Kiess M, Liaud M, Vilter H, Schomburg D, J Mol Biol. 1999 Oct 29;293(3):595-611. PMID:10543953
Page seeded by OCA on Thu Mar 20 13:37:55 2008
