S-methyl-5'-thioadenosine phosphorylase (MTAP)

Catalyzes the reversible phosphorylation of S-methyl-5'- thioadenosine (MTA) to adenine and 5-methylthioribose-1-phosphate. Involved in the breakdown of MTA, a significant by-product of polyamine biosynthesis.

Responsible for the initial step in the methionine salvage pathway after MTA was generated from S- adenosylmethionine. Has broad substrate specificity with 6- aminopurine nucleosides as preferred substrates.