The oxidoreductases LivQ and NeoQ are responsible for the different 6'-modifications in the aminoglycosides lividomycin and neomycin.

Aims: The 2-deoxystreptamine-containing aminoglycoside antibiotics (AGAs) constitute the largest subgroup of the aminoglycosides. Neomycin (NEO) and lividomycin (LIV) are both representatives of the pseudo-tetrasaccharide group among the NEO-type AGAs. While NEO contains a 6'-NH(2) group, the 6'-position remains unmodified in LIV.

Pleiotropic corepressors Sin3 and Ssn6 interact with repressor Opi1 and negatively regulate transcription of genes required for phospholipid biosynthesis in the yeast Saccharomyces cerevisiae.

Repressor protein Opi1 is required to negatively regulate yeast structural genes of phospholipid biosynthesis in the presence of precursor molecules inositol and choline (IC). Opi1 interacts with the paired amphipathic helix 1 (PAH1) of pleiotropic corepressor Sin3, leading to recruitment of histone deacetylases (HDACs). Mutational analysis of the Opi1-Sin3 interaction domain (OSID) revealed that hydrophobic OSID residues L56, V59 and V67 of Opi1 are indispensable for gene repression.