Table 1.

Analysis of functional divergence.

FD	Clades	Coefficient θ ± SE (p/R)	Critical Amino Acid Sites
Type I	Class 1 vs. Class 2	0.13 ± 0.04 (p = 8 × 10−4)	44, 127*, 245*, 351*,356, 435*
	Class 1-D1 vs. Class 1-D2	0.08 ± 0.05 (p = 0.95)	NA
	Class 1-D vs. Class 2-D	0.20 ± 0.05 (p = 1.3 × 10−5)	75, 120*, 186*, 245, 261, 325*, 351*, 356*, 393*, 435*, 445
	Class 1-M vs. Class 2-M	0.08 ± 0.05 (p = 0.54)	NA
Type II	Class 1 vs. Class 2	−0.18 ± 0.23 (R = 33)	NA
	Class 1-D1 vs. Class 1-D2	0.02 ± 0.13 (R = 13)	NA
	Class 1-D vs. Class 2-D	0.05 ± 0.13 (R = 41)	NA
	Class 1-M vs. Class 2-M	−0.02 ± 0.12 (R = 11)	NA

Functional divergences (θ) for pairwise comparisons of the HMT proteins are shown as values ± standard error. Five hundred and fifty-eight sites were investigated based on posterior probability (Qk) in FD I and posterior ratio in FD II within HMT proteins. Sites with Qk > 50% are listed relative to E. coli HMT aa protein sequence. Sites with * meant Qk > 70%. NA meant no data was detected.