Supplementary Table S1 Summary of oligonucleotide primers used.a

Primer	Sequence(5'to 3')
Q36E	CTGCACGGTCACCCTGAGACCCATGTC
H34N	GCTGTTGCTGCACGGTAATCCTCAGACCCATGTC
D104N	CTCTGCTGGCCCACAACCGTGGCGCCCGCGT
R105K	CTCTCTGCTGGCCCACGACAAAGGCGCCCGCGTTGCCCATC
R108K	CGACCGTGGCGCCAAAGTTGCCCATCGCC
D128N	GGTGCTGCTCAATATCGCGCCGACCTTG
I129A	GGTGCTGCTCGACGCCGCGCCGACCTTG
Y147F	GCATTTGCCCGCGCGTTTTGGCACTGGTTTTTCC
H149N	CATTTGCCCGCGCGTACTGGAATTGGTTTTTCCTGATTCGCC
W150A	CGCGCGTACTGGCACGCGTTTTTCCTGATTCGC
V175A	CCTATCTGCGCAGTGCGATGGGCAGTCGTAG
R179K	GCAGTGTGATGGGCAGTAAAAGTGCGGGGCTCAAACC
Y211F	GGGTATCTGCGAGGACTTCCGCGCCAGCGCCAG
H272N	CGTTGCCCGCCGGCAATTACCTTGCTGAA

aThe underlines indicate the mutagenized nucleotides, the shadows represent mutated amino acids

Supplementary Fig. S1 Michaelis-Menten function of TESH

Supplementary Fig. S2 Structural superposition among predicted TESH (chain A, green), 4nvr (chain A, pink), 4b9a (chain A, cyan), 3r3z (chain A, magenta), 6kxr (chain A, salmon), 7ac0 (chain A, yellow), 3qyj (chain A, olive), 1ehy (chain A, slate), 2CJP (chain A, gray), 3kd2 (chain A, teal). α-Helices are presented by spirals and β-strands by arrow. 4NVR,4B9A, 3R3Z, 6KXR, 7AC0, 3QYJ, 1EHY, 2CJP and 3KD2 possess 46%, 39%, 42%, 28%, 33%, 54%, 24%, 19% and 32% amino acid sequence identity with TESH, and their structure have a carbon alpha root mean square of 0.068 Å, 0.767 Å, 0.709 Å, 0.890 Å, 0.802 Å, 0.523 Å, 1.212 Å, 0.842 Å and 1.103 Å to TESH

Supplementary Fig. S3 Ramachandran plot of the modeled 3D structure of TESH. Residues appear as a square with the exception of glycine that appears as a triangle. Color codes are: red color -most favorable regions (A, B, L), yellow color -additional allowed regions (a, b, l, p), paled yellow -generously allowed regions (~a, ~b, ~l, ~p) and white color -disallowed regions

Supplementary Fig. S4 SDS-PAGE analysis of purification of TESH by immobilized metal affinity chromatograph. M, marker with protein masses of kDa from the top down