Bezsonova Irina, Rujan Iulian, Bobenchik April M, Gorbatyuk Vitaliy, Maciejewski Mark W, Gorbatyuk Oksana, Hao Bing, Arthanari Haribabu, Mamoun Choukri Ben, Hoch Jeffrey C
Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 6030-3305, USA.
Biomol NMR Assign. 2013 Apr;7(1):17-20. doi: 10.1007/s12104-012-9372-3. Epub 2012 Mar 6.
Phosphoethanolamine methyltransferases (PMTs also known as PEAMTs) catalyze the three-step s-adenosyl-methionione-dependent methylation of phosphoethanolamine to form phosphocholine. These enzymes play an important function in the synthesis of phosphatidylcholine, the major phospholipid in the membranes of lower and higher eukaryotes, as well as in the production of the compatible solute and osmoprotectant glycine betaine in plants. Genetic studies in plants, Caenhorhabditis elegans and Plasmodium falciparum have demonstrated that disruption of PMT activity results in severe defects in important cellular processes such as development, replication, survival and sexual maturation and differentiation. Here we report chemical shift assignments for PfPMT, the PMT from Plasmodium falciparum. X-ray crystal structures have been recently reported for complexes of PfPMT, but the structure of the apoenzyme remains unknown. The solution structure of the apoenzyme will help to elucidate important details of the mechanism of substrate binding by PfPMT, as residues comprising the substrate binding site are inaccessible to solvent in the conformation evident in the available crystal structures. In addition to enabling determination of the solution structure of the apoenzyme, the assignments will facilitate additional investigations into the interaction of PfPMT with its substrates and inhibitors.
磷酸乙醇胺甲基转移酶(PMT,也称为PEAMT)催化磷酸乙醇胺三步依赖S-腺苷甲硫氨酸的甲基化反应,生成磷酸胆碱。这些酶在磷脂酰胆碱(高等和低等真核生物膜中的主要磷脂)的合成中发挥重要作用,在植物中也参与相容性溶质和渗透保护剂甘氨酸甜菜碱的生成。对植物、秀丽隐杆线虫和恶性疟原虫的遗传学研究表明,PMT活性的破坏会导致发育、复制、存活以及性成熟和分化等重要细胞过程出现严重缺陷。在此,我们报告恶性疟原虫PMT(PfPMT)的化学位移归属。最近已报道了PfPMT复合物的X射线晶体结构,但脱辅基酶的结构仍未知。脱辅基酶的溶液结构将有助于阐明PfPMT底物结合机制的重要细节,因为在现有晶体结构中明显的构象下,构成底物结合位点的残基无法与溶剂接触。除了能够确定脱辅基酶的溶液结构外,这些归属还将有助于对PfPMT与其底物和抑制剂之间的相互作用进行进一步研究。