TDC, Tryptophan decarboxylase

Fig. 3. Biosynthesis of TIAs in C. roseus. Solid arrows indicate single enzymatic conversions, whereas dashed arrows indicate multiple enzymatic conversions. AS Anthranilate synthase, DXS D-l-deoxyxylulose 5-phosphate synthase G10H geraniol 10-hydroxylase CPR cytochrome P450 reductase TDC tryptophan decarboxylase STR strictosidine synthase SGD strictosidine /1-D-glucosidase D4H desacetoxyvindoline 4-hydroxylase DAT acetyl-CoA 4-O-deacetylvindoline 4-O-acetyl transferase. Genes regulated by ORCA3 are underlined. Reprinted with permission from [91]. Copyright (2000) American Association for the Advancement of Science...

Figure 1.3 Several pathways of secondary metabolites derive from precursors in the shikimate pathway. Abbreviation NPAAs, non-protein amino acids PAL, phenylalanine ammonia lyase TDC, tryptophan decarboxylase STS, strictosidine synthase CHS, chalcone synthase. (See Plate 2 in colour plate section.)...

Figure 2.9 Enzymic formation of ajmalicine. TDC, tryptophan decarboxylase STS, strictosidine synthase STG, strictosidine glucosidase POD, peroxidase.

Fig. (3). Compartmentalization of the biosynthetic pathway of terpenoid indole alkaloids in plant cells. G10H geraniol 16-hydroxylase SLS secologanin synthase TDC tryptophan decarboxylase STR strictosidine synthase SGD strictosidine P-D-glucosidade T16H tabersonine 16-hydroxylase OMT S-adenosyl - L-methionine 16-hydroxytabereonine - 16-O-methyltransferase NMT S-adenosyl - /.-methionine 16-methoxy - 2,3-dihydro-3-hydroxytabersonine - A -methyltransferase D4H desacetoxy vindoline 4-hydroxylase DAT acetylcoenzyme A 4-O-deacetylvindoline 4-O-aeetyltransferase PRX peroxidase.

Fig. (4). Early steps of the biosynthesis of terpenoid indole alkaloids in Catharanthus roseus. Triple arrowheads indicate multiple steps. G10H geraniol 16-hydroxylase TDC tryptophan decarboxylase STR strictosidine synthase.

The most importaiit enzymes on this model are TDC (tryptophan decarboxylase), GlOH (geraniol 10-hydroxylase) and SS (strictoside symthase). NADPH, PO (peroxidase), O (oxidase), and NADlf are all active in different Catharantus alkaloid formations. The biochemical models are subject to both qualitative and quantitative alkaloid analysis. Not all enzymes par-tieipating in alkaloid symthesis and degradation are yet known. Alkaloid enzymatology is, therefore, a growing research area. 

Fig. 8.5 Compartmentation of alkaloid biosynthesis in Cathamnthus roseus. AS anthianilate synthase, CR NADPH cathenamine reductase, DAT deacetylvindoline 17-O-acetyltransferase, ER endoplasmic reticulum, GlOH geraniol 10-hydroxylase, GAP glyceraldehyde-3-phosphate, NMT S-adenosyl-L-methionine methoxy-2, 16-dihydro-16-hydioxylagersonine-lV-methyltransferase, OHT desacetoxyvindoline-4-hydroxylase, SGD strictosidine -glucosidase, STR strictosidine synthase TDC tryptophan decarboxylase, THAS NADPH tetrahydroalstonine reductase (Adopted from Ref. [10])... 

Fig. 8.7 Biosynthetic pathway for monoteipenoid indole alkaloid (MIA) biosynthesis in plants. TDC tryptophan decarboxylase, STR strictosidine synthase, SGD strictosidine -o-glucosidase, T16H tabersonine 16-hydroxylase, D4H desacetoxyvindolme 4-hydroxylase, DAT deacetylvindoline 4-O-acetyltransferase (Adopted from Ref. [3])...

Figure 8,2 Terpenoid indole alkaloid biosynthetic pathway. AS anthranilate synthase TDC tryptophan decarboxylase ...

Figure 8.8 Camptothecin biosynthetic pathway. TDC tryptophan decarboxylase STR stric-tosidine synthase. The double arrows indicate multiple reactions, and the dashed arrows...

Figure 4.9 Biosynthesis of monoterpenoid indole alkaloids. Enzyme abbreviations TDC, tryptophan decarboxylase STR, strictosidine synthase SGD, strictosidine f-d-glucosidase T16H, tabersonine 16-hydroxylase D4H, desacetoxyvindoline 4-hydroxylase DAT, deacetylvindoline 4-O-acetyltransferase.

Figure 7.7 The relative location of c/s-elements and putative transcriptional regulators on the tryptophan decarboxylase (TDC), strictosidine synthase (STR), and cytochrome P450 reductase (CPR) gene promotors from Catharanthus roseus. The black box represents elements responsive to elicitor, jasmonate, or UV light. The white box represents a G-box motif, whereas the striped box represents a GCC-box element.

Fig. 8.1 Sequence of reactions and pathways involved in the biosynthesis of indole alkaloids in Catharanthus roseus. The dotted lines indicate multiple and/or uncharacterized enzyme steps. Tryptophan decarboxylase (TDC), Geraniol Hydroxylase (GH), Deoxyloganin synthase (DS), Secologanin Synthase (SLS) Strictosidine synthase (STR1), Strictosidine glucosidase (SG), Tabersonine-16-hydroxylase (T16H), Tabersonine 6,7-eposidase (T6,7E), Desacetoxyvindoline-4-hydroxylase (D4H), Deacetyl-vindoline-4-O-acetyltransferase (DAT) and Minovincinine-19-O-acetyltransferase (MAT) represent some of the enzyme steps that have been characterized.

Indole alkaloids are derived from tr)y)tophan, which is formed in the shiki-mate pathway. In the case of the terpenoid indoles, tryptophan is usually first converted to tiyptamine by the enzyme tryptophan decarboxylase (TDC) (Fig. 2.9). This enz)une occurs in the cytosol and has been detected in all parts of the developing seedling and in cell cultures of C. roseus (De Luca, 1993). If appears to be a pyridoxoquinoprotein, as two molecules of pyridoxal phosphafe and two molecules of covalently bound pyrroloquinoline quinone were found per enz)une molecule (Pennings et al, 1989). A tdc cDNA clone has been isolafed by immunoscreening of a C. roseus cDNA expression library (De... 

Figure 7.16 Phylogenetic relationships in key enzymes of pathways leading to SM, based on amino acid sequences, (a) Ornithine decarboxylase (ODC). (b) Tyrosine decarboxylase (TyrDC). (c) Tryptophan decarboxylase (TDC). (d) Phenylalanine ammonia-lyase (PAL). Numbers at nodes are bootstrap values.

Tryptophan is a product of the shikimate pathway and is converted into tryptamine by tryptophan decarboxylase (TDC), Fig. (4). TDC is a cytosolic soluble enzyme that occurs as a dimeric protein, and it was shown to exhibit a high substrate specificity and to be under post-translational control [46-52]. A cDNA clone encoding TDC was isolated by DeLuca et al. [53] and the full gene was characterized by Gooddijn et al. [54, 55] who found that TDC is encoded by a single copy gene without introns. The Tdc promoter has also been cloned and its regulation characterized [56, 57]. 

Mehrotra S, Srivastava V, Rahman LU, Kukieja AK. Overexpression of a Cathar-anthus tryptophan decarboxylase (tdc) gene leads to enhanced terpenoid indole alkaloid (TLA) production in transgenic hairy root lines of Rauwolfia serpenitina. Plant Cell Tiss Org Cult 2013 115(3) 377-84. 

Tryptophan decarboxylase (TDC) Camptotheca acuminata, Catharanthus roseus... 

---