5'-S-methyl-5'-thioadenosine

**5'-S-methyl-5'-thioadenosine (MTA)** is a naturally occurring sulfur-containing nucleoside found in all mammalian tissues and many other organisms. It is a by-product of polyamine biosynthesis, specifically generated from S‑adenosylmethioninamine and putrescine via spermidine synthase. MTA plays a key role in the methionine salvage pathway, where it is metabolized by the enzyme S-methyl‑5'‑thioadenosine phosphorylase (MTAP) to yield adenine and 5-methylthioribose‑1-phosphate. This process is crucial for recycling methionine and purines within cells. Accumulation of MTA can be toxic due to feedback inhibition of spermidine synthase, making its metabolism important for cellular homeostasis. MTAP deficiency or deletion occurs in various cancers, leading to increased intracellular levels of MTA[1][4][7][9].

Other names

5-Methylthioadenosine5'-Deoxy-5'-(methylthio)adenosine5'-MethylthioadenosineMTAS-Methyl-5'-thioadenosineThiomethyladenosineVitamin L2Adenylthiomethylpentose