Catalyzes the formation of S-adenosylmethionine from methionine and ATP. ATP + H2O + L-methionine = diphosphate + phosphate + S-adenosyl-L-methionine Amino-acid biosynthesis; S-adenosyl-L-methionine biosynthesis; S-adenosyl-L-methionine from L-methionine: step 1/1. Belongs to the AdoMet synthase 2 family.