Figure 4.

Comparison of amino acid sequences of TcSs and phylogenetic tree of N-methyltransferases. (A) Comparison of the amino acid sequences of TcS allelic variants. Residues liming the 1,3,7-trimethyluric acid binding pocket are highlighted by the yellow (conserved residues) and green dots (variable residues); residues that form direct hydrogen bond with 1,3,7-trimethyluric acid are labeled with a red box. (B) Phylogenetic tree of N-methyltransferases coding region sequences related to purine alkaloids in Camellia, Theobroma, and Coffea generated using the MEGA Program. Red, yellow and purple branches mark NMTs of Camellia, Theobroma, and Coffea. The green, blue, and red branches indicate TS, CS, and TcS.