Biosynthetic enzymes for the aminoglycosides butirosin and neomycin.

Butirosin and neomycin belong to a family of clinically valuable 2-deoxystreptamine (2DOS)-containing aminoglycoside antibiotics. The biosynthetic gene clusters for butirosin and neomycin were identified in 2000 and in 2005, respectively. In recent years, most of the enzymes encoded in the gene clusters have been characterized, and thus almost all the biosynthetic steps leading to the final antibiotics have been understood. This knowledge could shed light on the complex biosynthetic pathways for other related structurally diverse aminoglycoside antibiotics. In this chapter, the enzymatic reactions in the biosynthesis of butirosin and neomycin are reviewed step by step.