label: protein methylthiotransferase activity
label_lc: protein methylthiotransferase activity
description: "Catalysis of the reaction: 2 S-adenosyl-L-methionine + a [ribosomal protein S12] L-aspartate89 + a sulfurated [sulfur carrier] + a reduced electron acceptor = S-adenosyl-L-homocysteine + L-methionine + 5'-deoxyadenosine + 2 H+ + a [ribosomal protein S12] 3-methylthio-L-aspartate89 + an unsulfurated [sulfur carrier] + an oxidized electron acceptor."