1xg4
From Proteopedia
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| - | [[Image:1xg4.gif|left|200px]] | + | [[Image:1xg4.gif|left|200px]] |
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| - | '''Crystal Structure of the C123S 2-Methylisocitrate Lyase Mutant from Escherichia coli in complex with the inhibitor isocitrate''' | + | {{Structure |
| + | |PDB= 1xg4 |SIZE=350|CAPTION= <scene name='initialview01'>1xg4</scene>, resolution 1.6Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> and <scene name='pdbligand=ICT:ISOCITRIC ACID'>ICT</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Methylisocitrate_lyase Methylisocitrate lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.3.30 4.1.3.30] | ||
| + | |GENE= prpB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
| + | }} | ||
| + | |||
| + | '''Crystal Structure of the C123S 2-Methylisocitrate Lyase Mutant from Escherichia coli in complex with the inhibitor isocitrate''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1XG4 is a [ | + | 1XG4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XG4 OCA]. |
==Reference== | ==Reference== | ||
| - | Crystal structures of 2-methylisocitrate lyase in complex with product and with isocitrate inhibitor provide insight into lyase substrate specificity, catalysis and evolution., Liu S, Lu Z, Han Y, Melamud E, Dunaway-Mariano D, Herzberg O, Biochemistry. 2005 Mar 1;44(8):2949-62. PMID:[http:// | + | Crystal structures of 2-methylisocitrate lyase in complex with product and with isocitrate inhibitor provide insight into lyase substrate specificity, catalysis and evolution., Liu S, Lu Z, Han Y, Melamud E, Dunaway-Mariano D, Herzberg O, Biochemistry. 2005 Mar 1;44(8):2949-62. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15723538 15723538] |
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Methylisocitrate lyase]] | [[Category: Methylisocitrate lyase]] | ||
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[[Category: isocitrate lyase superfamily]] | [[Category: isocitrate lyase superfamily]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:09:21 2008'' |
Revision as of 13:09, 20 March 2008
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| , resolution 1.6Å | |||||||
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| Ligands: | and | ||||||
| Gene: | prpB (Escherichia coli) | ||||||
| Activity: | Methylisocitrate lyase, with EC number 4.1.3.30 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of the C123S 2-Methylisocitrate Lyase Mutant from Escherichia coli in complex with the inhibitor isocitrate
Overview
Two crystal structures of the C123S mutant of 2-methylisocitrate lyase have been determined, one with the bound reaction products, Mg(2+)-pyruvate and succinate, and the second with a bound Mg(2+)-(2R,3S)-isocitrate inhibitor. Comparison with the structure of the wild-type enzyme in the unbound state reveals that the enzyme undergoes a conformational transition that sequesters the ligand from solvent, as previously observed for two other enzyme superfamily members, isocitrate lyase and phosphoenolpyruvate mutase. The binding modes reveal the determinants of substrate specificity and stereoselectivity, and the stringent specificity is verified in solution using various potential substrates. A model of bound 2-methylisocitrate has been developed based on the experimentally determined structures. We propose a catalytic mechanism involving an alpha-carboxy-carbanion intermediate/transition state, which is consistent with previous stereochemical experiments showing inversion of configuration at the C(3) of 2-methylisocitrate. Structure-based sequence analysis and phylogenic tree construction reveal determinants of substrate specificity, highlight nodes of divergence of families, and predict enzyme families with new functions.
About this Structure
1XG4 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystal structures of 2-methylisocitrate lyase in complex with product and with isocitrate inhibitor provide insight into lyase substrate specificity, catalysis and evolution., Liu S, Lu Z, Han Y, Melamud E, Dunaway-Mariano D, Herzberg O, Biochemistry. 2005 Mar 1;44(8):2949-62. PMID:15723538
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