The metK protein plays a crucial role in cellular processes by catalyzing the formation of S-adenosylmethionine (AdoMet) from methionine and ATP This enzymatic activity involves a two-step process first synthesizing AdoMet and then hydrolyzing tripolyphosphate metK Protein Shigella sonnei (His) is the recombinant metK protein expressed by E coli with N-6 His labeled tag