2gcg
From Proteopedia
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| , resolution 2.200Å | |||||||
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| Ligands: | , , | ||||||
| Activity: | Glyoxylate reductase (NADP(+)), with EC number 1.1.1.79 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Ternary Crystal Structure of Human Glyoxylate Reductase/Hydroxypyruvate Reductase
Overview
Human glyoxylate reductase/hydroxypyruvate reductase (GRHPR) is a D-2-hydroxy-acid dehydrogenase that plays a critical role in the removal of the metabolic by-product glyoxylate from within the liver. Deficiency of this enzyme is the underlying cause of primary hyperoxaluria type 2 (PH2) and leads to increased urinary oxalate levels, formation of kidney stones and renal failure. Here we describe the crystal structure of human GRHPR at 2.2 A resolution. There are four copies of GRHPR in the crystallographic asymmetric unit: in each homodimer, one subunit forms a ternary (enzyme+NADPH+reduced substrate) complex, and the other a binary (enzyme+NADPH) form. The spatial arrangement of the two enzyme domains is the same in binary and ternary forms. This first crystal structure of a true ternary complex of an enzyme from this family demonstrates the relationship of substrate and catalytic residues within the active site, confirming earlier proposals of the mode of substrate binding, stereospecificity and likely catalytic mechanism for these enzymes. GRHPR has an unusual substrate specificity, preferring glyoxylate and hydroxypyruvate, but not pyruvate. A tryptophan residue (Trp141) from the neighbouring subunit of the dimer is projected into the active site region and appears to contribute to the selectivity for hydroxypyruvate. This first crystal structure of a human GRHPR enzyme also explains the deleterious effects of naturally occurring missense mutations of this enzyme that lead to PH2.
About this Structure
2GCG is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structural basis of substrate specificity in human glyoxylate reductase/hydroxypyruvate reductase., Booth MP, Conners R, Rumsby G, Brady RL, J Mol Biol. 2006 Jun 30;360(1):178-89. Epub 2006 May 22. PMID:16756993
Page seeded by OCA on Mon Mar 31 03:14:48 2008
