Ustilago sphaerogena

Amino acid Ustilago sphaerogena Neurospora crassaa) Saccharomyces cerevisiaea) Candida kreuseia)... 

Ferrichrome (as do also at least the members of the group for which structural data are available ((366) and references noted in Table 1) shows A-, synthetic euauf/o-ferrichrome based on o-Om A-configuration (253). Uptake studies performed with Ustilago sphaerogena (103) using and [ C]-ferrichrome under... 

Emery T (1971) Role of Ferrichrome as a Ferric lonophore in Ustilago sphaerogena. Biochemistry 10 1483... 

Ferrichrome was the first siderophore to be isolated and characterized from the fungi Ustilago sphaerogena in 1952. It is a cyclic hexapeptide with the sequence cycto[(Gly)3-(Al -acetyl-Af -hydroxy-L-ornithine)3] (1) . The biologically active ferrichromes form iron(ni) complexes with a left-handed A-cis helical twist. 

Tab. 12.1 Amount of iron solubilized from goethite by the two fungi Suillus granulatus and Ustilago sphaerogena (Watteau. Berthelin, 1990 with permission)...

RNases Source T, (Ref. 5) Aspergillus orryzae N, (Ref. 8) Neurospora crassa u, (Ref. 7) Ustilago sphaerogena u2 (Ref. 7) Ustilago sphaerogena t2 (Ref. 6) Aspergillus oryzae... 

Ribonuclease U2 is a novel enzyme found in the culture broth of Ustilago sphaerogena (7, 106). Ribonuclease U2 splits, practically specifically, the phosphodiester bonds of purine nucleotides in RNA with the intermediary formation of purine nucleoside 2, 3 -cyclic phosphates, indicating the specificity is complementary to that of pancreatic RNase A (106). Like RNase N, RNase U2 very slowly hydrolyzes the intermediate, nucleoside 2, 3 -cyclic phosphate, to 3 -nucleotides (80, 106). Thus, RNase U2 is a useful tool, not only for the analysis of nucleotide sequences of RNA (90, 92, 107, 108) but also for the synthesis of various oligonucleotides containing adenylyl or guanylyl residue (30) (T. Koike, T. Uchida, and F. Egami, unpublished). 

Arima et al. (7) have partially purified RNase U2 with RNases Ux and U3 from the culture broth (25 liters) of a strain of Ustilago sphaerogena, from which Glitz and Dekker had isolated a guanylori-bonuclease (109, 110). 

Neilands, J. B. A crystalline organo-iron pigment from a fungus, Ustilago sphaerogena. J. Am. Chem. Soc. 74, 4846 (1952). 

The authors are grateful to E. Stadtman for a gift of formyl phosphate and to J. B. Neilands for Ustilago sphaerogena. 

Emery T and Hoeeee PB (1980) Siderophore-medi-ated mechanism of gallium uptake demonstrated in the microorganism Ustilago sphaerogena. J Nucl Med 21 935-939. 

N -Hydroxy-L-orni thine ferrichrome Ustilago sphaerogena (43) ... 

As the prototypic member of microbial RNases, RNase T1 shares a similar catalytic mechanism and varying degrees of primary and, when known, tertiary structural identities with other guanylo-RNases, such as RNase U1 from Ustilago sphaerogena (39), RNase N1 from Neurospora crassa (39), and bamase from Bacillus amyloliquefaciens (48). 

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