Figure 3. Structural comparison of BthII1283 with other N-methyltransferases.

(A) Superimposition of HsTMT1 onto BthII1283. ( B) Superimposition of BgToxA onto BthII1283. The Class I methyltransferase fold is colored light gray. The N-terminal extension, first internal extension, and second internal extension of BthII1283 are colored salmon, light green, and light purple, respectively. The corresponding regions in HsNTMTl and BgToxA are colored dark red, dark green, and purple, respectively. SAH bound to BthII1283 is shown as balls and sticks.