5a19

Publication Abstract from PubMed

The principal methyl donor of the cell, S-adenosylmethionine (SAMe), is produced by the highly conserved family of methionine adenosyltranferases (MATs) via an ATP-driven process. These enzymes play an important role in the preservation of life, and their dysregulation has been tightly linked to liver and colon cancers. We present crystal structures of human MATalpha2 containing various bound ligands, providing a "structural movie" of the catalytic steps. High- to atomic-resolution structures reveal the structural elements of the enzyme involved in utilization of the substrates methionine and adenosine and in formation of the product SAMe. MAT enzymes are also able to produce S-adenosylethionine (SAE) from substrate ethionine. Ethionine, an S-ethyl analog of the amino acid methionine, is known to induce steatosis and pancreatitis. We show that SAE occupies the active site in a manner similar to SAMe, confirming that ethionine also uses the same catalytic site to form the product SAE.

Crystallography captures catalytic steps in human methionine adenosyltransferase enzymes.,Murray B, Antonyuk SV, Marina A, Lu SC, Mato JM, Hasnain SS, Rojas AL Proc Natl Acad Sci U S A. 2016 Feb 8. pii: 201510959. PMID:26858410^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.