Putrescine methyltransferase

Putrescine methyltransferase 2 methylputrescine oxidase 3 spontaneous reaction... 

ODC = ornithine decarboxylase PMT = putrescine methyltransferase MPO = methylputrescine oxidase OCT = ornithine carbamoyltransferase ADC = arginine decarboxylase AIH = agmatine iminohydrolase CPA =/v-carbaiTioylputrescine amidohydroiase SAM = S-adenosyl-methionine... 

Hibi et al. " have reported on putrescine A-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. 

Winz, R. A. and Baldwin, I. T. (2001). 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 A-methyltransferase transcripts. Plant Physiology 125 2189-2202. 

The first committed step in TA and nicotine biosynthesis is catalyzed by putrescine JV-methyltransferase (PMT) (Fig.7.4).82 A PMT cDNA isolated from tobacco showed extensive homology to spermidine synthase from mammalian and bacterial sources.83 A-Methylputrescine is oxidatively deaminated to 4-aminobutanal, which undergoes spontaneous cyclization to form the reactive A-methyl-A1-pyrrolinium cation. Although the enzymes involved are unknown, the A-methyl-A1-pyrrolinium cation is thought to condense either with acetoacetic acid to yield hygrine as a precursor to the tropane ring, or with nicotinic acid to form nicotine. 

HIBI, N FUJITA, T., HATANO, M., HASHIMOTO, T YAMADA, Y., Putrescine V-methyltransferase in cultured roots of Hyoscyamus albus. Plant Physiol., 1992,100, 826-835. 

SUZUKI, K YAMADA, Y, HASHIMOTO, T Expression of Atropa belladonna putrescine jV-methyltransferase gene in root pericycle. Plant Cell Physiol., 1999, 40,289-297. 

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). 

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 A-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]. 

Mizusaki, S., Y. Tanabe, M. Noguchi, and E. Tamaki Changes in the activities of ornithine decarboxylase, putrescine A-methyltransferase and A-methyl putrescine oxidase in tobacco roots in relation to nicotine biosynthesis Plant Cell Physiol. 14 (1973) 103-110. 

Martin, and A. Rodgman Effect of treatment of tobacco with ammonia or various ammonium salts on the levels of pyridines and pyrazines in smoke RDR, 1976, No. 3, January 29, see www.ijrtdocs.com 501003985 -4047. Mizusaki, S., Y. Tanabe, M. Noguchi, and E. Tamaki Phytochemical studies on tobacco alkaloids. XIV. The occurrence and properties of putrescine V-methyltransferase in tobacco roots Plant Cell Physiol. 12 (1971) 633-640. Mozayani, A. Phencychdine Effects on human performance and behavior, Eorensic Sd. Rev. 15 (2002) 61-73. Pailer, M. Chemistry of nicotine and related compounds (including biosynthetic aspects) in Tobacco alkaloids and related compounds, edited by U.S. Von Euler, MacMillan, New York, NY (1965) pp. 15-36. Pictet, A. and A. Rotschy Synthese des Nikotins [Synthesis of nicotine] Chem. Ber. 37 (1904) 1225-1235. 

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

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