An x-ray study indicated that microsomal prostaglandin E synthase type 2 (mPGES2) is a heme-bound protein and catalyzes prostaglandin (PG) H2 degradation, but not PGE2 formation (Yamada, T., and Takusagawa, F. (2007) Biochemistry 46, 8414-8424).
View Article and Find Full Text PDFS-adenosylmethionine (AdoMet) lies at an intersection of nucleotide and amino acid metabolism and performs a multitude of metabolic functions. AdoMet formation is catalyzed by S-adenosylmethionine synthetase (ATP: L-methionine S-adenosyltransferase (MAT)), which is a target for development of anticancer and antimicrobial agents. High affinity MAT inhibitors have been found through computational docking of more than 200000 compounds for predicted binding to the crystallographically defined nucleotide binding region of the enzyme's active site.
View Article and Find Full Text PDFCatalysis by S-adenosylmethionine synthetase has been investigated by quantum mechanical/molecular mechanical calculations, exploiting structures of the active crystalline enzyme. The transition state energy of +19.1 kcal/mol computed for a nucleophilic attack of the methionyl sulfur on carbon-5' of the nucleotide was indistinguishable from the experimental (solution) value when the QM residues were an uncharged histidine that hydrogen bonds to the leaving oxygen-5' and an aspartate that chelates a Mg2+ ion, and was similar (+18.
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