Structural overview of the SABATH and MES families.
A, chemical reaction of SA methylation and demethylation. AdoCys, S-adenosylhomocysteine. B, overall structure of the SA methyltransferase from C. breweri (Protein Data Bank code 1M6E) (65) shown as a ribbon diagram. C, close-up view of the SA methyltransferase active site. D, overall structure of the N. tabacum MES SABP2 (Protein Data Bank code 1Y7I) (71). E, active site view of N. tabacum SABP2 showing the positioning of SA and the catalytic triad.