2pvz
From Proteopedia
(New page: 200px<br /><applet load="2pvz" size="350" color="white" frame="true" align="right" spinBox="true" caption="2pvz, resolution 1.97Å" /> '''Crystal structure of...) |
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==Overview== | ==Overview== | ||
| - | In bacteria, the dehydration of 2-methylcitrate to yield 2-methylaconitate | + | In bacteria, the dehydration of 2-methylcitrate to yield 2-methylaconitate in the 2-methylcitric acid cycle is catalyzed by a cofactor-less (PrpD) enzyme or by an aconitase-like (AcnD) enzyme. Bacteria that use AcnD also require the function of the PrpF protein, whose function was previously unknown. To gain insights into the function of PrpF, the three-dimensional crystal structure of the PrpF protein from the bacterium Shewanella oneidensis was solved at 2.0 A resolution. The protein fold of PrpF is strikingly similar to those of the non-PLP-dependent diaminopimelate epimerase from Haemophilus influenzae, a putative proline racemase from Brucella melitensis, and to a recently deposited structure of a hypothetical protein from Pseudomonas aeruginosa. Results from in vitro studies show that PrpF isomerizes trans-aconitate to cis-aconitate. It is proposed that PrpF catalysis of the cis-trans isomerization proceeds through a base-catalyzed proton abstraction coupled with a rotation about C2-C3 bond of 2-methylaconitate, and that residue Lys73 is critical for PrpF function. The newly identified function of PrpF as a non-PLP-dependent isomerase, together with the fact that PrpD-containing bacteria do not require PrpF, suggest that the isomer of 2-methylaconitate that serves as a substrate of aconitase must have the same stereochemistry as that synthesized by PrpD. From this, it follows that the 2-methylaconitate isomer generated by AcnD is not a substrate of aconitase, and that PrpF is required to generate the correct isomer. As a consequence, the isomerase activity of PrpF may now be viewed as an integral part of the 2-methylcitric acid cycle. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Shewanella oneidensis]] | [[Category: Shewanella oneidensis]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Garvey, G | + | [[Category: Garvey, G S.]] |
| - | [[Category: Rayment, I | + | [[Category: Rayment, I R.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: EDO]] | [[Category: EDO]] | ||
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[[Category: unknown function]] | [[Category: unknown function]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:33:32 2008'' |
Revision as of 16:33, 21 February 2008
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Crystal structure of methylaconitate isomerase PrpF from Shewanella oneidensis
Overview
In bacteria, the dehydration of 2-methylcitrate to yield 2-methylaconitate in the 2-methylcitric acid cycle is catalyzed by a cofactor-less (PrpD) enzyme or by an aconitase-like (AcnD) enzyme. Bacteria that use AcnD also require the function of the PrpF protein, whose function was previously unknown. To gain insights into the function of PrpF, the three-dimensional crystal structure of the PrpF protein from the bacterium Shewanella oneidensis was solved at 2.0 A resolution. The protein fold of PrpF is strikingly similar to those of the non-PLP-dependent diaminopimelate epimerase from Haemophilus influenzae, a putative proline racemase from Brucella melitensis, and to a recently deposited structure of a hypothetical protein from Pseudomonas aeruginosa. Results from in vitro studies show that PrpF isomerizes trans-aconitate to cis-aconitate. It is proposed that PrpF catalysis of the cis-trans isomerization proceeds through a base-catalyzed proton abstraction coupled with a rotation about C2-C3 bond of 2-methylaconitate, and that residue Lys73 is critical for PrpF function. The newly identified function of PrpF as a non-PLP-dependent isomerase, together with the fact that PrpD-containing bacteria do not require PrpF, suggest that the isomer of 2-methylaconitate that serves as a substrate of aconitase must have the same stereochemistry as that synthesized by PrpD. From this, it follows that the 2-methylaconitate isomer generated by AcnD is not a substrate of aconitase, and that PrpF is required to generate the correct isomer. As a consequence, the isomerase activity of PrpF may now be viewed as an integral part of the 2-methylcitric acid cycle.
About this Structure
2PVZ is a Single protein structure of sequence from Shewanella oneidensis with and as ligands. Full crystallographic information is available from OCA.
Reference
The three-dimensional crystal structure of the PrpF protein of Shewanella oneidensis complexed with trans-aconitate: insights into its biological function., Garvey GS, Rocco CJ, Escalante-Semerena JC, Rayment I, Protein Sci. 2007 Jul;16(7):1274-84. Epub 2007 Jun 13. PMID:17567742
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