Crystal Structure and Catalytic Mechanism of CouO, a Versatile C-Methyltransferase from Streptomyces rishiriensis.

Friedel-Crafts alkylation of aromatic systems is a classic reaction in organic chemistry, for which regiospecific mono-alkylation, however, is generally difficult to achieve. In nature, methyltransferases catalyze the addition of methyl groups to a wide range of biomolecules thereby modulating the physico-chemical properties of these compounds. Specifically, S-adenosyl-L-methionine dependent C-methyltransferases possess a high potential to serve as biocatalysts in environmentally benign organic syntheses.

Crystallization of the novel S-adenosyl-L-methionine-dependent C-methyltransferase CouO from Streptomyces rishiriensis and preliminary diffraction data analysis.

Recombinant Q9F8T9 protein from Streptomyces rishiriensis (CouO), an S-adenosyl-L-methionine-dependent C-methyltransferase, has been successfully cloned, expressed and purified. CouO was crystallized from a single condition in the Morpheus crystallization screen. A vitrified crystal diffracted to 2.

Cytoplasmic recycling of 60S preribosomal factors depends on the AAA protein Drg1.

Allelic forms of DRG1/AFG2 confer resistance to the drug diazaborine, an inhibitor of ribosome biogenesis in Saccharomyces cerevisiae. Our results show that the AAA-ATPase Drg1 is essential for 60S maturation and associates with 60S precursor particles in the cytoplasm. Functional inactivation of Drg1 leads to an increased cytoplasmic localization of shuttling pre-60S maturation factors like Rlp24, Arx1, and Tif6.