The Chinese wheat mosaic virus coat protein was used in isolation to compare with Mg 2+ -binding protein-related sequences downloaded from the Uniprot database using the built-in MEME program. As can be seen in Table , the PPM-type domain is present throughout the coat protein sequence. The protein phosphatase serine/threonine phosphatase (PPM, IPR001932) requires Mg 2+ or Mn 2+ to dephosphorylate Ser and Thr residues. There are a Mg2+ binding sites, A243, in the PPM D coat protein of the Chinese wheat mosaic virus. Two domains of PK_Tyr_Ser-Thr in Table are shown to overlap with PPM , demonstrating that PPM is a serine phosphatase. FHA also showed significant overlap with PPM, which may have a phosphopeptide recognition function. The Mg2+ binding site A243 is present in metalloenzyme and shows that it has phosphatase catalytic activity, suggesting that it overlaps with PPM. The SpoIIE N showed significant overlap with the PPM-type and the Calponin homology domains, suggesting that PPM activation is connected to CH domain activity. The SpoIIE N and CBM20 share domains with the PPM protein, suggesting that its function is to stimulate the hydrolyzed starch and glycogenase activities.