1pta
From Proteopedia
(New page: 200px<br /><applet load="1pta" size="450" color="white" frame="true" align="right" spinBox="true" caption="1pta, resolution 2.1Å" /> '''THREE-DIMENSIONAL STR...) |
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| - | [[Image:1pta.jpg|left|200px]]<br /><applet load="1pta" size=" | + | [[Image:1pta.jpg|left|200px]]<br /><applet load="1pta" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1pta, resolution 2.1Å" /> | caption="1pta, resolution 2.1Å" /> | ||
'''THREE-DIMENSIONAL STRUCTURE OF PHOSPHOTRIESTERASE: AN ENZYME CAPABLE OF DETOXIFYING ORGANOPHOSPHATE NERVE AGENTS'''<br /> | '''THREE-DIMENSIONAL STRUCTURE OF PHOSPHOTRIESTERASE: AN ENZYME CAPABLE OF DETOXIFYING ORGANOPHOSPHATE NERVE AGENTS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Organophosphates, such as parathion and paraoxon, constitute the largest | + | Organophosphates, such as parathion and paraoxon, constitute the largest class of insecticides currently used in industrialized nations. In addition, many of these compounds are known to inhibit mammalian acetylcholinesterases thereby acting as nerve agents. Consequently, organophosphate-degrading enzymes are of considerable interest in light of their ability to detoxify such compounds. Here we report the three-dimensional structure of such an enzyme, namely, phosphotriesterase, as determined by single crystal X-ray diffraction analysis to 2.1-A resolution. Crystals employed in this investigation belonged to the space group P2(1)2(1)2 with unit cell dimensions of a = 80.3 A, b = 93.4 A, and c = 44.8 A and one molecule per asymmetric unit. The structure was solved by multiple isomorphous replacement with two heavy-atom derivatives and refined to a crystallographic R factor of 18.0%. As observed in various other enzymes, the overall fold of the molecule consists of an alpha/beta barrel with eight strands of parallel beta-pleated sheet. In addition, there are two antiparallel beta-strands at the N-terminus. The molecular model of phosphotriesterase presented here provides the initial structural framework necessary toward understanding the enzyme's broad substrate specificities and its catalytic mechanism. |
==About this Structure== | ==About this Structure== | ||
| - | 1PTA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Brevundimonas_diminuta Brevundimonas diminuta]. Full crystallographic information is available from [http:// | + | 1PTA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Brevundimonas_diminuta Brevundimonas diminuta]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PTA OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Benning, M.]] | [[Category: Benning, M.]] | ||
| - | [[Category: Holden, H | + | [[Category: Holden, H M.]] |
[[Category: hydrolase (organophosphate-degrading)]] | [[Category: hydrolase (organophosphate-degrading)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:32:19 2008'' |
Revision as of 12:32, 21 February 2008
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THREE-DIMENSIONAL STRUCTURE OF PHOSPHOTRIESTERASE: AN ENZYME CAPABLE OF DETOXIFYING ORGANOPHOSPHATE NERVE AGENTS
Overview
Organophosphates, such as parathion and paraoxon, constitute the largest class of insecticides currently used in industrialized nations. In addition, many of these compounds are known to inhibit mammalian acetylcholinesterases thereby acting as nerve agents. Consequently, organophosphate-degrading enzymes are of considerable interest in light of their ability to detoxify such compounds. Here we report the three-dimensional structure of such an enzyme, namely, phosphotriesterase, as determined by single crystal X-ray diffraction analysis to 2.1-A resolution. Crystals employed in this investigation belonged to the space group P2(1)2(1)2 with unit cell dimensions of a = 80.3 A, b = 93.4 A, and c = 44.8 A and one molecule per asymmetric unit. The structure was solved by multiple isomorphous replacement with two heavy-atom derivatives and refined to a crystallographic R factor of 18.0%. As observed in various other enzymes, the overall fold of the molecule consists of an alpha/beta barrel with eight strands of parallel beta-pleated sheet. In addition, there are two antiparallel beta-strands at the N-terminus. The molecular model of phosphotriesterase presented here provides the initial structural framework necessary toward understanding the enzyme's broad substrate specificities and its catalytic mechanism.
About this Structure
1PTA is a Single protein structure of sequence from Brevundimonas diminuta. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of phosphotriesterase: an enzyme capable of detoxifying organophosphate nerve agents., Benning MM, Kuo JM, Raushel FM, Holden HM, Biochemistry. 1994 Dec 20;33(50):15001-7. PMID:7999757
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