2pfl
From Proteopedia
(New page: 200px<br /><applet load="2pfl" size="450" color="white" frame="true" align="right" spinBox="true" caption="2pfl, resolution 2.90Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:2pfl.jpg|left|200px]]<br /><applet load="2pfl" size=" | + | [[Image:2pfl.jpg|left|200px]]<br /><applet load="2pfl" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2pfl, resolution 2.90Å" /> | caption="2pfl, resolution 2.90Å" /> | ||
'''CRYSTAL STRUCTURE OF PFL FROM E.COLI'''<br /> | '''CRYSTAL STRUCTURE OF PFL FROM E.COLI'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Pyruvate formate-lyase (PFL) from Escherichia coli uses a radical | + | Pyruvate formate-lyase (PFL) from Escherichia coli uses a radical mechanism to reversibly cleave the C1-C2 bond of pyruvate using the Gly 734 radical and two cysteine residues (Cys 418, Cys 419). We have determined by X-ray crystallography the structures of PFL (non-radical form), its complex with the substrate analog oxamate, and the C418A,C419A double mutant. The atomic model (a dimer of 759-residue monomers) comprises a 10-stranded beta/alpha barrel assembled in an antiparallel manner from two parallel five-stranded beta-sheets; this architecture resembles that of ribonucleotide reductases. Gly 734 and Cys 419, positioned at the tips of opposing hairpin loops, meet in the apolar barrel center (Calpha-Sgamma = 3.7 A). Oxamate fits into a compact pocket where C2 is juxtaposed with Cys 418Sgamma (3.3 A), which in turn is close to Cys 419Sgamma (3.7 A). Our model of the active site is suggestive of a snapshot of the catalytic cycle, when the pyruvate-carbonyl awaits attack by the Cys 418 thiyl radical. We propose a homolytic radical mechanism for PFL that involves Cys 418 and Cys 419 both as thiyl radicals, with distinct chemical functions. |
==About this Structure== | ==About this Structure== | ||
| - | 2PFL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with CL and NA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Formate_C-acetyltransferase Formate C-acetyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.54 2.3.1.54] Full crystallographic information is available from [http:// | + | 2PFL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=CL:'>CL</scene> and <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Formate_C-acetyltransferase Formate C-acetyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.54 2.3.1.54] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PFL OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Knappe, J.]] | [[Category: Knappe, J.]] | ||
[[Category: Schultz, S.]] | [[Category: Schultz, S.]] | ||
| - | [[Category: Wagner, A | + | [[Category: Wagner, A F.V.]] |
[[Category: CL]] | [[Category: CL]] | ||
[[Category: NA]] | [[Category: NA]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:28:55 2008'' |
Revision as of 16:29, 21 February 2008
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CRYSTAL STRUCTURE OF PFL FROM E.COLI
Overview
Pyruvate formate-lyase (PFL) from Escherichia coli uses a radical mechanism to reversibly cleave the C1-C2 bond of pyruvate using the Gly 734 radical and two cysteine residues (Cys 418, Cys 419). We have determined by X-ray crystallography the structures of PFL (non-radical form), its complex with the substrate analog oxamate, and the C418A,C419A double mutant. The atomic model (a dimer of 759-residue monomers) comprises a 10-stranded beta/alpha barrel assembled in an antiparallel manner from two parallel five-stranded beta-sheets; this architecture resembles that of ribonucleotide reductases. Gly 734 and Cys 419, positioned at the tips of opposing hairpin loops, meet in the apolar barrel center (Calpha-Sgamma = 3.7 A). Oxamate fits into a compact pocket where C2 is juxtaposed with Cys 418Sgamma (3.3 A), which in turn is close to Cys 419Sgamma (3.7 A). Our model of the active site is suggestive of a snapshot of the catalytic cycle, when the pyruvate-carbonyl awaits attack by the Cys 418 thiyl radical. We propose a homolytic radical mechanism for PFL that involves Cys 418 and Cys 419 both as thiyl radicals, with distinct chemical functions.
About this Structure
2PFL is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Formate C-acetyltransferase, with EC number 2.3.1.54 Full crystallographic information is available from OCA.
Reference
Structure and mechanism of the glycyl radical enzyme pyruvate formate-lyase., Becker A, Fritz-Wolf K, Kabsch W, Knappe J, Schultz S, Volker Wagner AF, Nat Struct Biol. 1999 Oct;6(10):969-75. PMID:10504733
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