Blasticidin structure

The bromide monohydrate was also used71 in establishing the crystal structure of blasticidin S. The dimensions of the unit cell (a =... 

Blasticidin (52) is an antibiotic isolated from Streptomyces griseochro-mogenes in 1955 [87]. Detailed physicochemical properties were reported in 1968, but the structure remained undefined [88]. Interest in this metabolite was renewed recently with the isolation of the homologous compounds aflastatin A and B (53, 54), metabolites of S. griseochro-... 

With the structures of aflastatin A (53) and B (N-demethyl aflastatin A, 54) secured, the structure of the related blasticidin A (52) was determined in a similar manner. Studies on the biosynthesis of aflastatin A... 

Six novel, cytosine nucleosides were isolated from the fermentation broth of S. griseochromogenes, which produces blasticidin S (55, see Scheme 22). The structural relationship between these nucleosides and cytosinine, the nucleoside moiety of blasticidin S, was investigated.87 One of these compounds was identified as l-(/3-D-glucopyrano-syluronic acid)cytosine (53). The presence of 53 was taken as evidence... 

The aminoaqfl-4-aminohexosyl-cytosine group of antibiotics is classified based on chemical structures (Fig. 4.11) each of which contains a cytosine base. Included in this group are blasticidin S, gougerotin, amicetin and bamicetin [46]. These antibiotics are not used therapeutically. However blasticidin S is an important antifungal used on rice crops. Only the crystal structure of blasticidin S bound to the ribosome is available. The chemical structure of blasticidin S resembles that of pep-tidyl-cytidine, although not as closely as puromycin resembles a tyrosylated adenosine (Fig. 4.11). 

In the crystal structure, blasticidin S binds to two sites on the ribosome (Fig. 4.13) and forms base-pairs with Hm G2284 and G2285 Ec 2251 and 2252). These two guanines are almost totally conserved residues of the P-loop, and are known to base pair with the CCA end of tRNA in order to position the P-site substrate in the peptidyl transferase center [47]. 

Fig.4. 13 Blasticidin S. Blasticidin S (purple) base pairs to the P-loop of rRNA (grey). Its guanidinium tail forms hydrogen bonds (dotted lines) to the phosphate and stacks hydrophobically onto the base of Hm A2474, a nucleotide that is protected from chemical modification (green) by blasticidin S. Superimposition of rRNA between crystal structures causes blasticidin S to become superimposed on C74 and C75 (yellow) of the analogue of a CCA end of tRNA. Fig. from [7].

Fig. 2.5 Structure of the human germ line (a), and rearranged (b) and targeted (c) IgH I locus of the G-line. The targeting vector used in homologous recombination contains the leptin-Fc reporter gene (hobFc) and the blasticidin deaminase...

Blasticidin S is an antibiotic of pyrimidine type, discovered in 19SS in the metabolites of Streptomyces griseochromogenes Fu i imgpetal., 1955). Blastiddin S, soluble in water, appears in the form of white needles. Its structure was eluddated by Yonehara and Otake (1966) S-[4-[3-amino-5-[(amino-imino-mcthyl)-methyl-amino]-1 -oxopentylj-amino]-1 -[4-amino-2-oxo-1 (2H)-pyrimidinyl]-1,2,3,4-tetrade-oxy- -D-er/7rohex-2-ene pyranuronic acid (9). 

Blasticidin S (327) is an antifungal agent used against rice blast disease in Japan. It was isolated in 1958 from Streptomyces griseochromogenes [411] and the structure and absolute stereochemistry were elucidated by chemical means [412-415] and confirmed by X-ray spectroscopy [416,417]. The biosynthesis has also been determined [418,419]. 

Blasticidin S (1) represents the first agricultural antibiotic developed in Japan. The compound has been isolated from culture broth of Streptomyces chriseochro-mogenes [2] and the chemical structure has been elucidated [3, 4]. Blasticidin S... 

Blasticidin S, 1 was isolated fiom Strefttottivces griseocltTomogcnes (1) as part of a major effort CO replace morcury-based compounds for the prevention of Pirit nlti arytue infection of rice plants in Japan (2). This fungus causes rice blast disease, a major rice pathogen in Japan and other parts of Asia. The structure and absolute stereochemistry of blast -cidirt S were determined by chemical degradation (3-6), and confirmed by x-ray diffraction (7,8). This work, as well as preliminary studies of blasticidin S biosynthesis, has been reviewed (9). 

Swaminathan V, Smith JL, Sundaraiiitgam M, Coutsogeorgopoulos C, Kartha G. Crystal and molecular structure of the antibiotic blasticidin S hydrochloride pentahydrate. Biochim Bio-phys Acta 1981 655 335-341. 

Kamakura T, Kobayashi K, Tanaka T, Yamaguchi I, Endo T. Cloning and expressiem a new structural gene for blasticidin 5 deaminase, a nucleoside aminohydrolase. A c Biol Chem 1987 51 3165-3168. 

A new nucleoside antibiotic arginomycin (20), isolated from S. arginensis, is structurally related to blasticidin... 

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