Table 2.

Reaction similarities between the predicted tetrahydropalmatine-producing reaction and its top 18 most similar, gene-annotated reactions from the BridgIT reference database.

Rank	BridgIT score	Predicted EC	Native substrate	Type of substrate	Native organism	Enzymes tested	Activity on THCB
1	0.98	2.1.1.291	(S)-reticuline	BIA	P. somniferum		Not tested
2	0.76	2.1.1.118	Columbamine	BIA	Coptis japonica	CjColOMT	Active
3	0.75	2.1.1.128	(S)-norcoclaurine	BIA	P. somniferum	Ps6OMT	Already in pathway, no activity
4	0.75	2.1.1.116	3′-Hydroxy-N-methyl-(S)-coclaurine	BIA	P. somniferum	Ps4’OMT	Already in pathway, no activity
					C. japonica	Cj4’OMT
					E. californica	Ec4’OMT
					T. flavum	Tf4’OMT
5	0.72	2.1.1.146	Isoeugenol	Phenylpropanoid	Ocimum basilicum (basil)		Not tested
6	0.69	2.1.1.38	O-demethylpuromycin	Antibiotic	Streptomyces alboniger	SaPurOMT	No activity
7	0.68	2.1.1.6	Catechol	Phenol	Diverse		Not tested
8	0.66	2.1.1.212	2,4′,7-Trihydroxy-isoflavanone	Flavanonoid	Lotus japonica	LjFlaOMT	No activity
9	0.64	2.1.1.4	N-acetylserotonin	Neurotransmitter	Homo sapiens (human)		Not tested
10	0.64	2.1.1.117	(S)-Scoulerine	BIA	P. somniferum	yPsS9OMT	Already in pathway, active
11	0.63	2.1.1.231	4′-Hydroxyflavone	Flavonoid	Glycine max (soybean)		Not tested
12	0.63	2.1.1.68	(E)-caffeate	Phenylpropanoid	Diverse		Not tested
13	0.62	2.1.1.104	Caffeoyl-CoA	Phenylpropanoid	Arabidopsis thaliana	AtCafOMT	No activity
14	0.61	2.1.1.150	(E)-caffeate	Phenylpropanoid	Medicago sativa (alfalfa)		Not tested
15	0.61	2.1.1.222	3-Demethylubiquinol	Quinone	Diverse bacteria		Not tested
16	0.60	2.1.1.279	trans-Anol	Phenol	Pimpinella anisum (anise)		Not tested
17	0.60	2.1.1.94	16-Hydroxytabersonine	Terpene indole alkaloid	Catharanthus roseus		Not tested
18	0.59	2.1.1.114	3,4-Dihydroxy-5-all-trans-polyprenylbenzoate	Quinone	Diverse, incl. S. cerevisiae		Natively present in yeast

In bold: Enzymes that act on (S)-tetrahydrocolumbamine (THCB).

EC Enzyme Commission classification number.