Gamma-L-glutamyl-butirosin B gamma-glutamyl cyclotransferase

γ- L -Glutamyl-butirosin B γ-glutamyl cyclotransferase (EC 4.3.2.6, btrG (gene)) is an enzyme with systematic name γ- L -glutamyl-butirosin B γ-glutamyl cyclotransferase (5-oxo- L -proline producing). This enzyme catalyses the following chemical reaction


 * γ- L -glutamyl-butirosin B $$\rightleftharpoons$$ butirosin B + 5-oxo- L -proline

The enzyme catalyses the last step in the biosynthesis of the aminoglycoside antibiotic butirosin B.