This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
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
