Crystal structure of glycerophosphodiester phosphodiesterase from Agrobacterium tumefaciens by SAD with a large asymmetric unit

Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
Proteins Structure Function and Bioinformatics (Impact Factor: 3.34). 11/2006; 65(2):514-8. DOI: 10.1002/prot.21079
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    ABSTRACT: Catabolism of glycerophospholipids during the rapid growth of the asexual intraerythrocytic malaria parasite may contribute to membrane recycling and the acquisition of lipid biosynthetic precursors from the host. To better understand the scope of lipid catabolism in Plasmodium falciparum, we have characterized a malarial homolog of bacterial glycerophosphodiesterases. These enzymes catalyze the hydrolysis of glycerophosphodiesterases that are generated by phospholipase-catalyzed removal of the two acyl groups from glycerophospholipids. The P. falciparum glycerophosphodiesterase (PfGDPD) exhibits an unusual tripartite distribution during the asexual blood stage with pools of enzyme in the parasitophorous vacuole, food vacuole and cytosol. Efforts to disrupt the chromosomal PfGDPD coding sequence were unsuccessful, which implies that the enzyme is important for efficient parasite growth. Tagging of the endogenous pool of PfGDPD with a conditional aggregation domain partially perturbed the distribution of the enzyme in the parasitophorous vacuole but had no discernable effect on growth in culture. Kinetic characterization of the hydrolysis of glycerophosphocholine by recombinant PfGDPD, an Mg2+-dependent enzyme, yielded steady-state parameters that were comparable to those of a homologous bacterial glycerophosphodiesterase. Together, these results suggest a physiological role for PfGDPD in glycerophospholipid catabolism in multiple subcellular compartments. Possibilities for what this role might be are discussed.
    Molecular and Biochemical Parasitology 11/2012; 186(1):29–37. DOI:10.1016/j.molbiopara.2012.09.004 · 2.24 Impact Factor
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    ABSTRACT: The glycerophosphodiester phosphodiesterases are evolutionarily conserved proteins that have been linked to several patho/ physiological functions, comprising bacterial pathogenicity and mammalian cell proliferation or differentiation. The bacterial enzymes do not show preferential substrate selectivities among the glycerophosphodiesters, and they are mainly dedicated to glycerophosphodiester hydrolysis, to produce glycerophosphate and alcohols, as the building blocks that are required for bacterial biosynthetic pathways. In some cases, this enzymatic activity has been demonstrated to contribute to bacterial pathogenicity, as with Hemophilus influenzae. Mammalian glyerophosphodiesterases have high substrate specificities even if the number of potential physiological substrates is continuously increasing. Some of these human enzymes have been directly linked to cell differentiation, as for GDE2, which triggers motor neuron differentiation, and for GDE3, the enzymatic activity of which is necessary and sufficient to induce osteoblast differentiation. Instead, GDE5 has been shown to inhibit skeletal muscle development independent of its enzymatic activity. This article is protected by copyright. All rights reserved.
    FEBS Journal 12/2013; DOI:10.1111/febs.12699 · 3.99 Impact Factor
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    ABSTRACT: periplasmic glycerophosphodiester phosphodiesterase, GlpQ. UgpQ has broad substrate specificity toward various glycerophosphodiesters, producing sn-glycerol-3-phosphate and the corresponding alcohols. UgpQ accumulates under conditions of phosphate starvation, suggesting that it allows the utilization of glycerophos- phodiesters as a source of phosphate. These results clarify how E. coli utilizes glycerophosphodiesters using two homologous enzymes, UgpQ and GlpQ. Glycerophosphodiesters are enzymatically produced by phospholipases A1 and A2 from membrane phospholipids (10, 25). There are several glycerophosphodiesters, based on the alcohol moiety: glycerophosphocholine (GPC), glycerophos- phoethanolamine (GPE), glycerophosphoinositol (GPI), glyc- erophosphoserine (GPS), glycerophosphoglycerol (GPG), and so on. Glycerophosphodiesters are further degraded by glyc- erophosphodiester phosphodiesterase (EC, produc- ing the corresponding alcohols and sn-glycerol-3-phosphate (G3P), which is an essential precursor for de novo synthesis of glycerophospholipids. In the metabolic pathway of Escherichia coli, glycerophosphodiesters are thought to be utilized by two distinct systems. One is the Glp system, and the other is the Ugp system (26). In each system, related proteins are encoded by one or more operons. They contain genes that code for transporter proteins and enzymes. The glpTQ operon simultaneously regulates the transcrip- tion of related genes (13). GlpT, an ABC transporter, actively transports G3P from the periplasm into the cytosol through the plasma membrane. glpQ codes for a periplasmic glycerophos- phodiester phosphodiesterase. GlpQ processes periplasmic glycerophosphodiesters into G3P and corresponding alcohols (14). The other glycerophosphodiester-utilizing system is the Ugp system. The ugp operon is constituted of ugpB, ugpA, ugpE, ugpC, and ugpQ (4, 19). UgpB specifically binds to glycero- phosphodiesters and delivers them to the membrane trans- porter. UgpA, UgpE, and UgpC constitute the transporter for glycerophosphodiesters. UgpQ, a 27-kDa protein, is a cytosolic glycerophosphodiester phosphodiesterase and is homologous to GlpQ.