Structural highlights
Function[PPS_THEKO] Catalyzes the conversion of (R)-4-phosphopantoate and beta-alanine to 4'-phosphopantothenate in the CoA biosynthesis pathway. Cannot use (R)-pantoate as substrate and thus does not display pantothenate synthetase (PS) activity. Publication Abstract from PubMedBacteria/eukaryotes share a common pathway for coenzyme A biosynthesis which involves two enzymes to convert pantoate to 4'-phosphopantothenate. These two enzymes are absent in almost all archaea. Recently, it was reported that two novel enzymes, pantoate kinase (PoK) and phosphopantothenate synthetase (PPS), are responsible for this conversion in archaea. Here, we report the crystal structure of PPS from the hyperthermophilic archaeon, Thermococcus kodakarensis and its complexes with substrates, ATP, and ATP and 4-phosphopantoate (PPo). PPS forms an asymmetric homodimer, in which two monomers composing a dimer, deviated from the exact 2-fold symmetry, displaying 4 degrees -13 degrees distortion. The structural features are consistent with the mutagenesis data and the results of biochemical experiments previously reported. Based on these structures, we discuss the catalytic mechanism by which PPS produces phosphopantoyl adenylate (PPA), which is thought to be a reaction intermediate. (c) Proteins 2014;. (c) 2014 Wiley Periodicals, Inc. Crystal Structure of Phosphopantothenate Synthetase from Thermococcus k odakarensis.,Kishimoto A, Kita A, Ishibashi T, Tomita H, Yokooji Y, Imanaka T, Atomi H, Miki K Proteins. 2014 Mar 17. doi: 10.1002/prot.24546. PMID:24638914[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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