Crystal structure of human pyrroline-5-carboxylate reductase.

Abstract

Pyrroline-5-carboxylate reductase (P5CR) is a universal housekeeping enzyme that catalyzes the reduction of Delta(1)-pyrroline-5-carboxylate (P5C) to proline using NAD(P)H as the cofactor. The enzymatic cycle between P5C and proline is very important for the regulation of amino acid metabolism, intracellular redox potential, and apoptosis. Here, we present the 2.8 Angstroms resolution structure of the P5CR apo enzyme, its 3.1 Angstroms resolution ternary complex with NAD(P)H and substrate-analog. The refined structures demonstrate a decameric architecture with five homodimer subunits and ten catalytic sites arranged around a peripheral circular groove. Mutagenesis and kinetic studies reveal the pivotal roles of the dinucleotide-binding Rossmann motif and residue Glu221 in the human enzyme. Human P5CR is thermostable and the crystals were grown at 37 degrees C. The enzyme is implicated in oxidation of the anti-tumor drug thioproline.

• Authors: Zhaohui Meng, Zhiyong Lou, Zhe Liu, Ming Li, Xiaodong Zhao, Mark Bartlam, Zihe Rao
• Journal: Journal of molecular biology (J Mol Biol) Vol. 359 Issue 5 Pg. 1364-77 (Jun 23 2006) ISSN: 0022-2836 [Print] Netherlands
• PMID: 16730026 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Pyrroline Carboxylate Reductases

Topics

• Amino Acid Sequence
• Binding Sites (genetics)
• Dimerization
• Humans
• Models, Molecular
• Molecular Sequence Data
• Mutagenesis (genetics)
• Protein Structure, Secondary
• Pyrroline Carboxylate Reductases (antagonists & inhibitors, chemistry)
• Sequence Alignment
• Streptococcus pyogenes (enzymology)
• delta-1-Pyrroline-5-Carboxylate Reductase