1bgp
From Proteopedia
(New page: 200px<br /><applet load="1bgp" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bgp, resolution 1.90Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1bgp.gif|left|200px]]<br /><applet load="1bgp" size=" | + | [[Image:1bgp.gif|left|200px]]<br /><applet load="1bgp" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bgp, resolution 1.90Å" /> | caption="1bgp, resolution 1.90Å" /> | ||
'''CRYSTAL STRUCTURE OF BARLEY GRAIN PEROXIDASE 1'''<br /> | '''CRYSTAL STRUCTURE OF BARLEY GRAIN PEROXIDASE 1'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of the major peroxidase of barley grain (BP 1) has | + | The crystal structure of the major peroxidase of barley grain (BP 1) has been solved by molecular replacement and phase combination and refined to an R-factor of 19.2% for all data between 38 and 1.9 A. The refined model includes amino acid residues 1-309, one calcium ion, one sodium ion, iron-protoporphyrin IX, and 146 solvent molecules. BP 1 has the apparently unique property of being unable to catalyze the reaction with the primary substrate hydrogen peroxide to form compound I at pH values > 5, a feature investigated by obtaining crystal structure data at pH 5.5, 7.5, and 8.5. Structural comparison shows that the overall fold of inactive barley grain peroxidase at these pH values resembles that of both horseradish peroxidase C and peanut peroxidase. The key differences between the structures of active horseradish peroxidase C and inactive BP 1 include the orientation of the catalytic distal histidine, disruption of a hydrogen bond between this histidine and a conserved asparagine, and apparent substitution of calcium at the distal cation binding site with sodium at pH 7.5. These profound changes are a result of a dramatic structural rearrangement to the loop region between helices B and C. This is the first time that structural rearrangements linked to active site chemistry have been observed by crystallography in the peroxidase domain distal to heme. |
==About this Structure== | ==About this Structure== | ||
| - | 1BGP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare] with CA, NA and HEM as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Peroxidase Peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.7 1.11.1.7] Full crystallographic information is available from [http:// | + | 1BGP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=NA:'>NA</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Peroxidase Peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.7 1.11.1.7] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BGP OCA]. |
==Reference== | ==Reference== | ||
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[[Category: peroxidase]] | [[Category: peroxidase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:55:05 2008'' |
Revision as of 09:55, 21 February 2008
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CRYSTAL STRUCTURE OF BARLEY GRAIN PEROXIDASE 1
Overview
The crystal structure of the major peroxidase of barley grain (BP 1) has been solved by molecular replacement and phase combination and refined to an R-factor of 19.2% for all data between 38 and 1.9 A. The refined model includes amino acid residues 1-309, one calcium ion, one sodium ion, iron-protoporphyrin IX, and 146 solvent molecules. BP 1 has the apparently unique property of being unable to catalyze the reaction with the primary substrate hydrogen peroxide to form compound I at pH values > 5, a feature investigated by obtaining crystal structure data at pH 5.5, 7.5, and 8.5. Structural comparison shows that the overall fold of inactive barley grain peroxidase at these pH values resembles that of both horseradish peroxidase C and peanut peroxidase. The key differences between the structures of active horseradish peroxidase C and inactive BP 1 include the orientation of the catalytic distal histidine, disruption of a hydrogen bond between this histidine and a conserved asparagine, and apparent substitution of calcium at the distal cation binding site with sodium at pH 7.5. These profound changes are a result of a dramatic structural rearrangement to the loop region between helices B and C. This is the first time that structural rearrangements linked to active site chemistry have been observed by crystallography in the peroxidase domain distal to heme.
About this Structure
1BGP is a Single protein structure of sequence from Hordeum vulgare with , and as ligands. Active as Peroxidase, with EC number 1.11.1.7 Full crystallographic information is available from OCA.
Reference
Structure of barley grain peroxidase refined at 1.9-A resolution. A plant peroxidase reversibly inactivated at neutral pH., Henriksen A, Welinder KG, Gajhede M, J Biol Chem. 1998 Jan 23;273(4):2241-8. PMID:9442067
Page seeded by OCA on Thu Feb 21 11:55:05 2008
Categories: Hordeum vulgare | Peroxidase | Single protein | Henriksen, A. | CA | HEM | NA | Chromoprotein | Oxidoreductase
