Biosynthetic pathways with

Sofia HJ, Chen G, Hetzler BG, et al. 2001. Radical SAM, a novel protein superfanuly linking unresolved steps in familiar biosynthetic pathways with radical mechanisms functional characterization using new analysis and information visualization methods. Nucleic Acids Res 29 1097-106. 

There are many branches to the flavonoid biosynthetic pathways, with the best characterized being those leading to the colored anthocyanins and proanthocyanidins (PAs) and the generally colorless flavones, flavonols, and isoflavonoids. Genes or cDNAs have now been identified for all the core steps leading to anthocyanin, flavone, and flavonol formation, as well as many steps of the isoflavonoid branch, allowing extensive analysis of the encoded enzymes (Table 3.1). In addition, several DNA sequences are available for the modification enzymes that produce the variety of structures known within each class of compound. 

Shimada, Y. et al.. Genetic engineering of the anthocyanin biosynthetic pathway with flavonoid-3, 5 -hydroxylase specific switching of the pathway in petunia. Plant Cell Rep., 20, 456, 2001. 

Understand the purine and pyrmidine de novo biosynthetic pathways, with special attention to enzymes controlling pathway rates and the properties of such enzymes the positive and negative effectors steps inhibited by the various antitumor agents and their mechanisms final products of the de novo pathways and how the various nucleotides are generated from them and the biosynthesis of deoxyribonucleotides and the attendant mechanisms. 

A mixture of (35,45)-[4— H]-mevalonate and (3/ ,4/ )-[4— H]-mevalonate and ( )-[2— C]-mevalonate [( )-463 ] was fed to whole plants of C. japonica by the cotton-wick method (Scheme 62). The ratio of to T of the labelled tutin (11 ) showed that one of the three tritium atoms survived the biosynthetic pathway, with the other two tritium atoms lost to oxidation. For the tritium at position C(4) it is only possible for it to remain if the hydrogen transfer occurs in a one-step reaction. In the case of a double 1,2-hydrogen transfer, the tritium atom would be incorporated in the isopropyl group and vanish with the dehydrogenation to the... 

Kohler JJ, Czlapinski JL, Laughlin ST, Schelle MW, de Graffenried CL, Bertozzi CR. Directing flux in glycan biosynthetic pathways with a small molecule switch. ChemBioChem. 2004 5 1455-1458. 

Numerous studies performed with E. coli have established that, in E. coli, biotin regulates very efficiently its biosynthetic pathway, with an absolute specificity, the biotin vitamers being inactive. As the topics has been largely reviewed, it will be only summarized here. The regulation occurs at the transcriptional level and the biotin operon repressor (BirA) has been well characterized. This 33.5 kDa bifiinctional protein is both an enzyme and a transcriptional regulator (Figure 21). It activates biotin into biotinyl-5 -AMP with ATP (reaction a) and transfers biotin on a specific lysine residue of the biotin accepting proteins (in E. coli, the biotin carboxyl carrier protein (BCCP), a subunit of acetyl-CoA carboxylase) (reaction b). When all the... 

For the past 20 years, there has been a growing interest in applying the in vitro culture of plant cells, tissues and organs to the study of medicinal plants. Main topics include the development of culture for the large-scale production of valuable chemicals, the discovery of new biologically active metabolites, the selection of plants showing favourable characteristics of productivity, the elucidation of biosynthetic pathways with isolation of... 

L-isoleucine, and L-tryptophan was observed, suggesting that 123 likely shares a common biosynthetic pathway with the paraherquamides as shown in Fig. (28). Prenylation of the cyc/o-L-tryptophan-L-13-methylproline and intramolecular [4+2] cyclization (via 126) would provide the putative bicyclo[2,2,2] core (127). Williams and coworkers have already demonstrated that 127 serves as a biosynthetic precursor to paraherquamide A (146) shown in Fig. (33). Oxidation of 127 leads to the catechol derivative (128). Oxidative cleavage of four carbon atoms from the oxygenated aromatic ring in 128 could furnish the spirosuccinimide ring of 123. 

They stimulate carotenoid biosynthetic pathways with no apparent herbicidal activity. A substantial amount of information on structure-activity relationships for bioregulation of carotenoids in higher plants has been developed. 

The open-chain tetrapyrrole chromophores of phycobiliproteins (Fig. 2) share a common biosynthetic pathway with heme and chlorophyll from 5-aminole-vulinate to protoporphyrin IX (a pathway also shared by phytochrome of higher plants). Each phycobilipro-tein consists of a- and 3-chains. The M, of these polypeptides varies among species, but the a-chain (M,... 

The biosynthesis of simple stilbenes has been found out, and it shared a similar biosynthetic pathway with the flavonoids. Taking resveratrol for example, it starts from a cinnamoyl-CoA unit and extended the chain with three malonyl-CoA molecules (Scheme 62.1) [105]. Then, the resveratrol structure is produced by aldol reaction with the presence of stilbene synthase. Nevertheless, the flavonoids are formed depending on chalcone synthase and Claisen reaction. 

Urbaniak MD, Yashunsky DV, Crossman A et al (2008) Probing enzymes late in the trypanosomal glycosylphosphatidylinositol biosynthetic pathway with synthetic glycosylpho-sphatidylinositol analogues. ACS Chem Biol 3 625-634... 

Fig. 7. Cellular Overview of the LPG Biosynthetic Pathway with respect to the Suh-cellular Localization, constructed using Cell Designer. The enzymes, for which the literature data was also not available, were considered to he within the cytosol. ...

When L-valine-l- C was added to suspensions of washed mycehum of the Cephalosporium sp. the specific radioactivity of extraceUular penicilhn N reached a maximum within a few minutes and then began to fall. The specific radioactivity of cephalosporin C continued to increase for some time while that of penicilhn N was fading, but the apparent specific radioactivities of the two antibiotics did not follow a course which could be interpreted in terms of a product-precursor relationship between them. However, some uncertainty attended the quantitative aspects of these experiments, in which the amounts of antibiotics were deduced from biological assay and their radioactivities from counts on paper after electrophoresis and chromatography (Warren et al., I967). Whether cephalosporin C is formed from penicilhn N is thus still an open question, although it would be difficult to reconcile this biosynthetic pathway with the apparent abihty of D-valine to depress selectively the production of penicilhn N. 

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