Table 1. All different gene/enzyme descriptions used in this study.
| Gene Abbreviation | Respective Enzyme name or Class | EC Number | Source [Ref] | Substrate specificity | Desirable product |
|---|---|---|---|---|---|
| (A) Genetically modified tyrosine overproduction pathway (as shown in Fig 1A) | |||||
| AroA | 5-Enolpyruvoylshikimate 3-phosphate synthase | 2.5.1.19 | Escherichia coli [29] | shikimate-3-phosphate | 5-enolpyruvoylshikimate 3-phosphate |
| AroB | Dehydroquinate synthase | 4.2.3.4 | E. coli [29] | 3-deoxy-D-arabino-heptulosonate | dehydroquinate |
| AroC | Chorismate synthase | 4.2.1.10 | E. coli [29] | 5-enolpyruvoylshikimate 3-phosphate | chorismate |
| AroD | Dehydroquinate dehydratase | 1.1.1.25 | E. coli [29] | dehydroquinate | dehydroshikimate |
| AroE | Shikimate dehydrogenase | 2.5.1.19 | E. coli [29] | dehydroshikimate | shikimate |
| AroG | 3-Deoxy-D-arabino-heptulosonate synthase | 2.5.1.54 | E. coli [29] | phosphoenol pyruvate and erythrose 4-phosphate | 3-deoxy-D-arabino-heptulosonate |
| AroL | Shikimate kinase | 2.7.1.71 | E. coli [29] | shikimate | shikimate 3-phosphate |
| PpsA | Phosphoenolpyruvate synthase | 2.7.9.2 | E. coli [29] | pyruvate | phosphoenol pyruvate |
| TktA | Transketolase A | 2.2.1.1 | E. coli [29] | fructose 6-phosphate and glyceraldehyde 3-phosphate | erythrose 4-phosphate |
| TyrA | Chorismate mutase/prephenate dehydrogenase | 1.3.1.12 | E. coli [29] | chorismate, prephenate | prephenate, 4-Hydroxyphenyl pyruvate |
| TyrB | Tyrosine aminotransferase | 2.6.1.5 | E. coli [29] | 4-hydroxyphenyl pyruvate | tyrosine |
| YdiB | Quinate/shikimate dehydrogenase | 1.1.1.282 | E. coli [29] | dehydroshikimate | shikimate |
| (B) HT heterologous pathway (as shown in Fig 1B) | |||||
| ALR-K (previously named yahK [30]) | Aldehyde reductase (ALR) | 1.1.1.2 | E. coli [30] | hydroxyphenyl acetaldehyde | tyrosol |
| dihydroxyphenyl acetaldehyde | hydroxytyrosol | ||||
| ALR-D (previously named yqhD [30]) | 1.1.1.21 | E. coli [30] | hydroxyphenyl acetaldehyde | tyrosol | |
| dihydroxyphenyl acetaldehyde | hydroxytyrosol | ||||
| AAS / PcAAS (previously named TDC / PcTDC [31]) | Aromatic Acetaldehyde Synthase (AAS) | Petroselinum crispum [31] | L-tyrosine | 4-hydroxyphenyl acetaldehyde (4-HPA) | |
| L-DOPA (L-3,4-dihydroxyphenylalanine) | 3,4-dihydroxyphenyl acetaldehyde (3,4-DHPAA) | ||||
| TYR / RsTYR | Tyrosinase | 1.14.18.1 | Ralstonia solanacearum [32] | L-tyrosine | L-DOPA |
| tyrosol | hydroxytyrosol | ||||
Enzyme protein classes used throughout the text along with the source of the gene and main biochemical information. EC numbers were extracted from BRENDA database [33].