Putrescine N methyltransferase

WINZ, R.A., BALDWIN, I.T., Molecular interactions between the specialist herbivore Manduca sexta (Lepidoptera, Sphingidae) and its natural host Nicotiana attenuata. IV. Insect-Induced ethylene reduces jasmonate-induced nicotine accumulation by regulating putrescine N-methyltransferase transcripts. Plant Physiol., 2001,125,2189-2202. 

VOELCKEL, C., KRUEGEL, T., GASE, K HEIDRICH, N VAN DAM, N.M., WINZ, R., BALDWIN, I.T., Anti-sense expression of putrescine N-methyltransferase confirms defensive role of nicotine in Nicotiana sylvestris against Manduca sexta Chemoecology, 2001,11,121-126. 

RIECHERS, D. E., TIMKO, M. P., Structure and expression of the gene family encoding putrescine N-methyltransferase in Nicotiana tabacum New clues to the evolutionary origin of cultivated tobacco., Plant Mol.Biol., 1999,41,387-401. 

Figure 2.2 Biosynthesis of nicotine and anabasine. ODC, ornithine decarboxylase ADC, arginine decraboxylase PMT, putrescine N-methyltransferase DAO, diamine oxidase MPO, N-methylputresdne oxidase.

Several enzymes of tropane alkaloid biosynthesis have been purified and characterized from root cultures namely, putrescine N-methyltransferase from D. stramonium (Walfon et al, 1994) and H. niger (Hibi et al, 1992) and fropinone reducfases I and II from Atropa belladonna (Drager and Schaal, 1994), D. stramonium (Porfsfeffen et al, 1992, 1994) and H. niger (Hashimoto and Yamada, 1994). TR I and TR II have been characterized by X-ray crystallography (Nakajima et al, 1998). 

Hibi, N., Fujita, T., Hatano, M., Hashimoto, T. and Yamada, Y. (1992) Putrescine N-methyltransferase in cultured roots of Hyoscyamus albus. Plant Physiol., 100, 826-35. 

Suzuki, K., Yamada, Y. and Hashimoto, T. (1999) Expression of Atropa belladonna putrescine N-methyltransferase gene in root pericycle. Plant Cell Physiol, 40,289-97. 

Teuber, M., Azemi, M.E., Namjoyan, R, Meier, A.-C., Wodak, A., Brandt, W. and Drager, B. (2007) Putrescine N-methyltransferases - a structure-function analysis. Plant Mol. Biol, 63, 787-801. 

Figure 3 (a) Representative tropane and nicotine alkaloids, (b) Tropane biosynthesis. ODC, ornithine decarboxylase PMT, putrescine N-methyltransferase MPO, diamine oxidase TRl, tropinone reductase 1 H6H, hyocyamine 6b-hydroxylase. 

Atropa belladonna plants have been transformed with an H6H clone from H. niger. A. belladonna normally produces high levels of hyoscyamine, the precursor for the more pharmaceutically valuable alkaloid scopolamine (Fig. 3b). However, after transformation with the H6H gene, transgenic A. belladonna plants were shown to accumulate scopolamine almost exclusively (164). Additionally, the levels of tropane alkaloid production in a variety of hairy root cultures were altered by overexpression of methyltransferase putrescine-N-methyltransferase and H6H. Overexpression of both of these enzymes in a hairy root cell culture resulted in significant increases in scopolamine production (164, 165). Fluorinated phenyllactic acid substrates... 

Hashimoto T, Shoji T, Mihara T, Oguri H, Tamaki K, Suzuki Kl, Yamada Y. Intraspecific variability of the tandem repeats in Nicotiana putrescine N-methyltransferases. Plant Mol. Biol. 1998 37 25-37. 

Teuber M, Azemi ME, Namjoyan F, Meier A-C, Wodak A, Brandt W, Drager B. Putrescine N-methyltransferases—a structure-function analysis. Plant Mol. Biol. 2007 63 787-801. McLauchlan WR, McKee RA, Evans DM. The purification and immunocharacterization of N-methylputrescine oxidase from transformed root cultures of Nicotinia tabacum. Planta 1993 191 440-445. 

Putrescine N-methyltransferase (PMT, EC 2.1.1.53) catalyses the first specific step in the biosynthesis of tropane alkaloids, cocaine and nicotine [123]. Putrescine is methylated by PMT via SAM (S-adenosylmethionine) transferring the methyl group from SAM to an amino group of putrescine, Fig. (1). This enzyme has been isolated from roots of both Nicotiana tabacum and D. stramonium [124], and the activity of this enzyme is restricted to the roots of Solanaceous species corroborated by results describing a root pericycle-specific activity in A. belladonna [125]. Nevertheless, more recently, a low mRNA pmt transcript level in leaves of N. tabacum, with a rise in transcript level after mechanical wounding has been detected [126],... 

Putrescine N-methyltransferase Atropa belladonna S-adenosylmethionine-dependent N-methyltrantfsrase a< SE... 

Hibi et al. reported on putrescine N-methyltransferase isolated from the nicotine biosynthetic pathway coded by cDNA. Recent advances in cell and molecular biology of alkaloid biosynthesis have heightened awareness of the genetic importance. 

Walton NJ, Peerless ACJ, Robins RJ, Rhodes MJC, Boswell HD, Robins DJ. Purification and properties of putrescine N-methyltransferase from transformed roots of... 

Putrescine N-methyltransferase (PMT, EC 2.1.1.53) is another key enzyme of the tropane alkaloid pathway and is involved in putrescine N-methylation leading to the first specific precursor of tropane alkaloids [32]. Several reports suggested that PMT is a flux-limiting of the tropane alkaloid pathway [32-35]. 

Hashimoto, T., Yukimime, Y. and Yamada, Y. (1989) Putrescine and putrescine N-methyltransferase in the biosynthesis of tropane alkaloids in cultured roots of Hyocyamus albus I. Biochemical studies. Planta. 178, 123-130. 

Rothe, G., Hachiya, A., Yamada, Y., Hashimoto, T., and Drager, B. (2003) Alkaloids in plants and root cultures of Atropa belladonna overexpressing putrescine N-methyltransferase. J. Exp. Bot. 54, 2065-2070. 

The main alkaloid found in tobacco plants, nicotine, is composed of a pyrrolidine ring and a pyridine ring (Fig. 5). The pyrrolidine moiety is derived from Y-methylputrescine, which is formed from putrescine by putrescine N-methyltransferase (PMT) (Katoh et al., 2005). The pyridine moiety of nicotine is derived Irom nicotinic acid. Nicotine is exclusively synthesized in the roots and is translocated to the leaves via the xylem. Multiple structural genes... 

Shoji T, Yamada Y, Hashimoto T (2000) Jasmonate induction of putrescine N-methyltransferase genes in the root of Nicotiana sylvestris. Plant Cell Physiol 41 831-839... 

Figure 4.6 Biosynthesis of tropane alkaloids and nicotine. Enzyme abbreviations ODC, ornithine decarboxylase PMT, putrescine N-methyltransferase TR-i, tropinone reductase-i TR-ii, tropinone reductase-ii EHGiH, hyoscyamine 6f -hydroxylase.

A. General Route of Calystegine Biosynthesis Putrescine N-Methyltransferase Tropinone Reductases... 

Figure 6 Tropane alkaloid bios)mthetic pathway. Three arrows indicate that more than one enzymatic step leads to the next metabolite. PMT = putrescine N-methyltransferase DAO = diamine oxidase TRI = tropine forming tropinone reductase TRII = pseudotropine forming tropinone reductase.

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