1ld3: Difference between revisions
New page: left|200px<br /><applet load="1ld3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ld3, resolution 2.60Å" /> '''Crystal Structure of... |
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[[Image:1ld3.gif|left|200px]]<br /><applet load="1ld3" size=" | [[Image:1ld3.gif|left|200px]]<br /><applet load="1ld3" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1ld3, resolution 2.60Å" /> | caption="1ld3, resolution 2.60Å" /> | ||
'''Crystal Structure of B. subilis ferrochelatase with Zn(2+) bound at the active site.'''<br /> | '''Crystal Structure of B. subilis ferrochelatase with Zn(2+) bound at the active site.'''<br /> | ||
==Overview== | ==Overview== | ||
Ferrochelatase, the terminal enzyme in heme biosynthesis, catalyses metal | Ferrochelatase, the terminal enzyme in heme biosynthesis, catalyses metal insertion into protoporphyrin IX. The location of the metal binding site with respect to the bound porphyrin substrate and the mode of metal binding are of central importance for understanding the mechanism of porphyrin metallation. In this work we demonstrate that Zn(2+), which is commonly used as substrate in assays of the ferrochelatase reaction, and Cd(2+), an inhibitor of the enzyme, bind to the invariant amino acids His183 and Glu264 and water molecules, all located within the porphyrin binding cleft. On the other hand, Mg(2+), which has been shown to bind close to the surface at 7 A from His183, was largely absent from its site. Activity measurements demonstrate that Mg(2+) has a stimulatory effect on the enzyme, lowering K(M) for Zn(2+) from 55 to 24 micro M. Changing one of the Mg(2+) binding residues, Glu272, to serine abolishes the effect of Mg(2+). It is proposed that prior to metal insertion the metal may form a sitting-atop (SAT) complex with the invariant His-Glu couple and the porphyrin. Metal binding to the Mg(2+) site may stimulate metal release from the protein ligands and its insertion into the porphyrin. | ||
==About this Structure== | ==About this Structure== | ||
1LD3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ferrochelatase Ferrochelatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.99.1.1 4.99.1.1] Full crystallographic information is available from [http:// | 1LD3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ferrochelatase Ferrochelatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.99.1.1 4.99.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LD3 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Al-Karadaghi, S.]] | [[Category: Al-Karadaghi, S.]] | ||
[[Category: Fodje, M | [[Category: Fodje, M N.]] | ||
[[Category: Hansson, A.]] | [[Category: Hansson, A.]] | ||
[[Category: Hansson, M.]] | [[Category: Hansson, M.]] | ||
[[Category: Lecerof, D.]] | [[Category: Lecerof, D.]] | ||
[[Category: Leon, R | [[Category: Leon, R A.]] | ||
[[Category: Olsson, U.]] | [[Category: Olsson, U.]] | ||
[[Category: Ryde, U.]] | [[Category: Ryde, U.]] | ||
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[[Category: rossmann fold]] | [[Category: rossmann fold]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:43:53 2008'' | ||
Revision as of 14:43, 21 February 2008
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Crystal Structure of B. subilis ferrochelatase with Zn(2+) bound at the active site.
OverviewOverview
Ferrochelatase, the terminal enzyme in heme biosynthesis, catalyses metal insertion into protoporphyrin IX. The location of the metal binding site with respect to the bound porphyrin substrate and the mode of metal binding are of central importance for understanding the mechanism of porphyrin metallation. In this work we demonstrate that Zn(2+), which is commonly used as substrate in assays of the ferrochelatase reaction, and Cd(2+), an inhibitor of the enzyme, bind to the invariant amino acids His183 and Glu264 and water molecules, all located within the porphyrin binding cleft. On the other hand, Mg(2+), which has been shown to bind close to the surface at 7 A from His183, was largely absent from its site. Activity measurements demonstrate that Mg(2+) has a stimulatory effect on the enzyme, lowering K(M) for Zn(2+) from 55 to 24 micro M. Changing one of the Mg(2+) binding residues, Glu272, to serine abolishes the effect of Mg(2+). It is proposed that prior to metal insertion the metal may form a sitting-atop (SAT) complex with the invariant His-Glu couple and the porphyrin. Metal binding to the Mg(2+) site may stimulate metal release from the protein ligands and its insertion into the porphyrin.
About this StructureAbout this Structure
1LD3 is a Single protein structure of sequence from Bacillus subtilis with as ligand. Active as Ferrochelatase, with EC number 4.99.1.1 Full crystallographic information is available from OCA.
ReferenceReference
Metal binding to Bacillus subtilis ferrochelatase and interaction between metal sites., Lecerof D, Fodje MN, Alvarez Leon R, Olsson U, Hansson A, Sigfridsson E, Ryde U, Hansson M, Al-Karadaghi S, J Biol Inorg Chem. 2003 Apr;8(4):452-8. Epub 2003 Jan 18. PMID:12761666
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