1mgt
From Proteopedia
(New page: 200px<br /><applet load="1mgt" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mgt, resolution 1.8Å" /> '''CRYSTAL STRUCTURE OF ...) |
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| - | [[Image:1mgt.gif|left|200px]]<br /><applet load="1mgt" size=" | + | [[Image:1mgt.gif|left|200px]]<br /><applet load="1mgt" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1mgt, resolution 1.8Å" /> | caption="1mgt, resolution 1.8Å" /> | ||
'''CRYSTAL STRUCTURE OF O6-METHYLGUANINE-DNA METHYLTRANSFERASE FROM HYPERTHERMOPHILIC ARCHAEON PYROCOCCUS KODAKARAENSIS STRAIN KOD1'''<br /> | '''CRYSTAL STRUCTURE OF O6-METHYLGUANINE-DNA METHYLTRANSFERASE FROM HYPERTHERMOPHILIC ARCHAEON PYROCOCCUS KODAKARAENSIS STRAIN KOD1'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of O6-methylguanine-DNA methyltransferase (EC | + | The crystal structure of O6-methylguanine-DNA methyltransferase (EC 2.1.1.63) of hyperthermophilic archaeon Pyrococcuskodakaraensis strain KOD1 (Pk -MGMT) was determined by single isomorphous replacement method with anomalous scattering (SIRAS) at 1.8 A resolution. The archaeal protein is extremely thermostable and repairs alkylated DNA by suicidal alkyl transfer from guanine O6 to its own cysteine residue. Archaea constitute the third primary kingdom of living organisms, sharing characteristics with procaryotic and eucaryotic cells. They live in various extreme environments and are thought to include the most ancient organisms on the earth. Structural studies on hyperthermophilic archaeal proteins reveal the structural features essential for stability under the extreme environments in which these organisms live, and will provide the structural basis required for stabilizing various mesophilic proteins for industrial applications. Here, we report the crystal structure of Pk-MGMT and structural comparison of Pk-MGMT and methyltransferase homologue from Escherichia coli (AdaC, C-terminal fragment of Ada protein). Analyses of solvent-accessible surface area (SASA) reveals a large discrepancy between Pk-MGMT and AdaC with respect to the property of the ASA. In the Pk-MGMT structure, the intra-helix ion-pairs contribute to reinforce stability of alpha-helices. The inter-helix ion-pairs exist in the interior of Pk-MGMT and stabilize internal packing of tertiary structure. Furthermore, structural features of helix cappings, intra and inter-helix ion-pairs are found around the active-site structure in Pk-MGMT. |
==About this Structure== | ==About this Structure== | ||
| - | 1MGT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermococcus_kodakarensis Thermococcus kodakarensis] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Methylated-DNA--[protein]-cysteine_S-methyltransferase Methylated-DNA--[protein]-cysteine S-methyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.63 2.1.1.63] Full crystallographic information is available from [http:// | + | 1MGT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermococcus_kodakarensis Thermococcus kodakarensis] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Methylated-DNA--[protein]-cysteine_S-methyltransferase Methylated-DNA--[protein]-cysteine S-methyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.63 2.1.1.63] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MGT OCA]. |
==Reference== | ==Reference== | ||
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[[Category: suicidal enzyme]] | [[Category: suicidal enzyme]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:55:02 2008'' |
Revision as of 11:55, 21 February 2008
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CRYSTAL STRUCTURE OF O6-METHYLGUANINE-DNA METHYLTRANSFERASE FROM HYPERTHERMOPHILIC ARCHAEON PYROCOCCUS KODAKARAENSIS STRAIN KOD1
Overview
The crystal structure of O6-methylguanine-DNA methyltransferase (EC 2.1.1.63) of hyperthermophilic archaeon Pyrococcuskodakaraensis strain KOD1 (Pk -MGMT) was determined by single isomorphous replacement method with anomalous scattering (SIRAS) at 1.8 A resolution. The archaeal protein is extremely thermostable and repairs alkylated DNA by suicidal alkyl transfer from guanine O6 to its own cysteine residue. Archaea constitute the third primary kingdom of living organisms, sharing characteristics with procaryotic and eucaryotic cells. They live in various extreme environments and are thought to include the most ancient organisms on the earth. Structural studies on hyperthermophilic archaeal proteins reveal the structural features essential for stability under the extreme environments in which these organisms live, and will provide the structural basis required for stabilizing various mesophilic proteins for industrial applications. Here, we report the crystal structure of Pk-MGMT and structural comparison of Pk-MGMT and methyltransferase homologue from Escherichia coli (AdaC, C-terminal fragment of Ada protein). Analyses of solvent-accessible surface area (SASA) reveals a large discrepancy between Pk-MGMT and AdaC with respect to the property of the ASA. In the Pk-MGMT structure, the intra-helix ion-pairs contribute to reinforce stability of alpha-helices. The inter-helix ion-pairs exist in the interior of Pk-MGMT and stabilize internal packing of tertiary structure. Furthermore, structural features of helix cappings, intra and inter-helix ion-pairs are found around the active-site structure in Pk-MGMT.
About this Structure
1MGT is a Single protein structure of sequence from Thermococcus kodakarensis with as ligand. Active as [protein-cysteine_S-methyltransferase Methylated-DNA--[protein]-cysteine S-methyltransferase], with EC number 2.1.1.63 Full crystallographic information is available from OCA.
Reference
Hyperthermostable protein structure maintained by intra and inter-helix ion-pairs in archaeal O6-methylguanine-DNA methyltransferase., Hashimoto H, Inoue T, Nishioka M, Fujiwara S, Takagi M, Imanaka T, Kai Y, J Mol Biol. 1999 Sep 24;292(3):707-16. PMID:10497033 [[Category: Methylated-DNA--[protein]-cysteine S-methyltransferase]]
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