Nectria haematococca

Substantial attention has been devoted to the metabolism of 5-fluorouracil and related compounds. For example, F NMR was used successfully both in cell extracts and in whole mycelia to elucidate anabolic reactions involving pyrimidine nucleotides and degradation to a-fluoro-p-alanine in the fungus Nectria haematococca (Parisot et al. 1989,1991). 

Parisot D, MC Malet-Martino, P Crasnier, R Martino (1989) nuclear magnetic resonance analysis of 5-fluorouracil metabolism in wild-type and 5-fluorouracil-resistant Nectria haematococca. Appl Environ Microbiol 55 2474-2479. 

Fluoro-2 -deoxyuridine has been extensively used in studies of the mechanism of action of thymidylate synthase, and 5-fluorouracil is an anticancer drug that has provided a lead to the development of others. The metabolism of 5-fluorouracil by the ascomycete fungus Nectria haematococca has been studied using F NMR (Parisot et al. 1991). a-Fluoro-P-alanine (2-fluoro-3-aminopropionate) was produced (Figure 10.27), while 5-fluorouridine-5 -mono-, di-, and triphosphate were found in acid extracts of the mycelia, and the 2 - and 3 -monophosphates were recovered from RNA. 

Enkerli, J., Bhatt, G., and Covert, S.F., Maackiain detoxification contributes to the virulence of Nectria haematococca MP VI on chickpea, Mol. Plant-Microbe Interact., 11, 317, 1998. 

Wasmann, C.C. and Van Etten, H.D., Transformation-mediated chromosome loss and disruption of a gene for pisatin demethylase decrease the virulence of Nectria haematococca on pea, Mol Plant-Microbe Interact., 9, 793, 1996. 

He, J., Ruan, Y., and Straney, D., Analysis of determinants of binding and transcriptional activation of the pisatin-responsive DNA binding factor of Nectria haematococca, Mol Plant-Microbe Interact., 9, 171, 1996. 

Pisatin (6.23) is an isoflavonoid phytoalexin that is synthesized by pea (Pisum sativum L.) as a response to infection (Preisig et al., 1989). Subsequently, it was shown that pathogens capable of demethylating pisatin were tolerant of this phytoalexin. The enzyme responsible for demethylation is a specific cytochrome P450 mono-oxygenase released by the fungus Nectria haematococca (Delserone et al., 1999). 

Straney, D.C., Van Etten, H.D. Characterization of the PDA1 promoter of Nectria haematococca and identification of a region that binds a pisatin-responsive DNA binding factor. Mol Plant Microb Interact 1994 7 256-266. 

There are few natural representatives of this system. Albidin is a fungistatic red pigment isolated from Penicillium albidum and an X-ray analysis has shown that it has structure 146 (86JCS(P1)1145). From the fungus Nectria haematococca, in addition to the previously known quinones, a new one, nectriafurone (147), was isolated (83PI30I). From 2.5 kg of the root bark of... 

Parisot, D., M.C. Malet-Martino, R. Martino, and P. Crasnier. 1991.19F nuclear magnetic resonance analysis of 5-fluorouracil metabolism in four differently pigmented strains of Nectria haematococca. Appl. Environ. Microbiol. 57 3605-3612. 

The degradation of 5-fluorouracil by the fungus Nectria haematococca proceeds by the established pathway for the nonfluorinated compound with the formation of the stable a-fluoro-( -alanine (Parisot et al. 1991). 

Scheme 4. Structures of the phytoalexins pisatin (1) and maackiain (2) from peas directed against the pathogenic fungus Nectria haematococca.

FAD monoox., maackiain detoxification Nectria haematococca) ACC49410 31/3e-15... 

GA gibberellin, A aspergillus, C Candida, F fusarium, N haematococca— Nectria haematococca, P phanerochaete, S saccharomyces, T trichosporon... 

George HL, Hirschi KD, VanEtten HD (1998) Biochemical properties of the products of cytochrome P450 genes (PDA) encoding pisatin demethylase activity in Nectria haematococca. Arch Microbiol 170 147-154... 

Isol. from leaves of Trifolium pratense as fungal metab. Also prod, by cultures of Ascochyta pisi, Botrytis cinerea, Fusarium spp., Nectria haematococca and other fungi. Mp 178-181° dec. -h337° (c, 0.944 in EtOH). 3-Me, 8,9-methylenedioxy ether [20186-22-5]. 6di-Hydroxy-3-methoxy-S,9-methylenedioxypterocarpan. Pisatin Stress metab. from Caragana spp., Lathyrus spp., Pisum fulvum, P. sativum, Tephrosia bidwilli and Trifolium pratense. Phytoalexin. Cryst. (EtOH or C H ). Mp 61°. [a]g +280° (c, 0.11 in EtOH). 

However, a different approach was used to obtain arylacetonitrilases from fungi such as A. uiger, N. crassa, Aspergillus oryzae, Nectria haematococca, and Arihroderma henhamiae. The selected genes were synthetically prepared and expressed in E. coU, being optimized according to the codon bias in this host [7, 8, 31]. 

Kolattukudy, P.E. D.L. Gamble. 1995. Nectria haematococca. In Pathogenesis and Host Specificity in Plant Diseases—Histological, Biochemical, Genetic and Molecular Bases, Vol. II Eukaryotes, eds. K. Kohmoto, U.S. Singh R.P. Singh, pp. 83-101, Pergamon, Elsevier, New York. 

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