Catalyzes the formation of methanethiol and 1-deoxy-D-xylulose 5-phosphate (DXP) from 1-methylthioxylulose 5-phosphate (MTXu-5P) (PubMed:23042035, PubMed:23035785). Involved in the MTA-isoprenoid shunt of the methionine salvage pathway (PubMed:23042035). AH2 + S-methyl-1-thio-D-xylulose 5-phosphate = 1-deoxy-D-xylulose 5-phosphate + A + methanethiol Amino-acid biosynthesis; L-methionine biosynthesis via salvage pathway. Metabolic intermediate biosynthesis; 1-deoxy-D-xylulose 5-phosphate biosynthesis. Mutant does not release methanethiol and does not show an increase in 1-deoxy-D-xylulose 5-phosphate formation after 5'-methylthioadenosine (MTA) feeding. Mutant accumulates a mixture of 1-methylthioxylulose 5-phosphate (MTXu-5P) and 1-methylthioribulose 5-phosphate (MTRu-5P) (PubMed:23042035). Inactivation of the gene increases ethylene production from MTA-grown cells (PubMed:29133429).