2hji
From Proteopedia
(New page: 200px<br /><applet load="2hji" size="350" color="white" frame="true" align="right" spinBox="true" caption="2hji" /> '''Structural model for the Fe-containing isofo...) |
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==Overview== | ==Overview== | ||
| - | Acireductone dioxygenase (ARD) catalyzes different reactions between O2 | + | Acireductone dioxygenase (ARD) catalyzes different reactions between O2 and 1,2-dihydroxy-3-oxo-5-(methylthio)pent-1-ene (acireductone) depending upon the metal bound in the active site. Ni2+ -ARD cleaves acireductone to formate, CO and methylthiopropionate. If Fe2+ is bound (ARD'), the same substrates yield methylthioketobutyrate and formate. The two forms differ in structure, and are chromatographically separable. Paramagnetism of Fe2+ renders the active site of ARD' inaccessible to standard NMR methods. The structure of ARD' has been determined using Fe2+ binding parameters determined by X-ray absorption spectroscopy and NMR restraints from H98S ARD, a metal-free diamagnetic protein that is isostructural with ARD'. ARD' retains the beta-sandwich fold of ARD, but a structural entropy switch increases order at one end of a two-helix system that bisects the beta-sandwich and decreases order at the other upon interconversion of ARD and ARD', causing loss of the C-terminal helix in ARD' and rearrangements of residues involved in substrate orientation in the active site. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Klebsiella oxytoca]] | [[Category: Klebsiella oxytoca]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chai, S | + | [[Category: Chai, S C.]] |
[[Category: Ju, T.]] | [[Category: Ju, T.]] | ||
| - | [[Category: Maroney, M | + | [[Category: Maroney, M J.]] |
| - | [[Category: Pochapsky, T | + | [[Category: Pochapsky, T C.]] |
[[Category: FE2]] | [[Category: FE2]] | ||
[[Category: dioxygenase]] | [[Category: dioxygenase]] | ||
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[[Category: structural entropy]] | [[Category: structural entropy]] | ||
| - | ''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 17:42:32 2008'' |
Revision as of 15:42, 21 February 2008
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Structural model for the Fe-containing isoform of acireductone dioxygenase
Overview
Acireductone dioxygenase (ARD) catalyzes different reactions between O2 and 1,2-dihydroxy-3-oxo-5-(methylthio)pent-1-ene (acireductone) depending upon the metal bound in the active site. Ni2+ -ARD cleaves acireductone to formate, CO and methylthiopropionate. If Fe2+ is bound (ARD'), the same substrates yield methylthioketobutyrate and formate. The two forms differ in structure, and are chromatographically separable. Paramagnetism of Fe2+ renders the active site of ARD' inaccessible to standard NMR methods. The structure of ARD' has been determined using Fe2+ binding parameters determined by X-ray absorption spectroscopy and NMR restraints from H98S ARD, a metal-free diamagnetic protein that is isostructural with ARD'. ARD' retains the beta-sandwich fold of ARD, but a structural entropy switch increases order at one end of a two-helix system that bisects the beta-sandwich and decreases order at the other upon interconversion of ARD and ARD', causing loss of the C-terminal helix in ARD' and rearrangements of residues involved in substrate orientation in the active site.
About this Structure
2HJI is a Single protein structure of sequence from Klebsiella oxytoca with as ligand. Active as Acireductone dioxygenase (Fe(2+)-requiring), with EC number 1.13.11.54 Full crystallographic information is available from OCA.
Reference
One protein, two enzymes revisited: a structural entropy switch interconverts the two isoforms of acireductone dioxygenase., Ju T, Goldsmith RB, Chai SC, Maroney MJ, Pochapsky SS, Pochapsky TC, J Mol Biol. 2006 Nov 3;363(4):823-34. Epub 2006 Aug 26. PMID:16989860
Page seeded by OCA on Thu Feb 21 17:42:32 2008
